<PAGE>

                                                                     EXHIBIT 4.5

                      STOCK AND WARRANT PURCHASE AGREEMENT

         This STOCK AND WARRANT PURCHASE AGREEMENT is dated as of the 6th day of
September, 2000 by and between Kana Communications, Inc., a Delaware corporation
with its principal office at 740 Bay Road, Redwood City, California (the
"Company" or "Kana"), and Andersen Consulting LLP, an Illinois limited liability
partnership, with an office at 1661 Page Mill Rd., Palo Alto, California (the
"Purchaser").

         WHEREAS, the Company desires to issue and sell to the Purchaser an
aggregate of 400,000 shares (the "SHARES") of the authorized but unissued shares
of common stock, $.001 par value per share, of the Company (the "COMMON STOCK");
and

         WHEREAS, the Company desires to issue and sell to the Purchaser a
warrant (the "Warrant") to purchase an aggregate of up to 725,000 shares (the
"Warrant Shares") of the authorized but unissued shares of the Common Stock; and

         WHEREAS, the Purchaser wishes to purchase the Shares and the Warrant
(collectively with the Warrant Shares, referred to as the "Securities"), on the
terms and subject to the conditions set forth in this Agreement.

         NOW THEREFORE, in consideration of the mutual agreements,
representations, warranties and covenants herein contained, the parties hereto
agree as follows:

         1.   DEFINITIONS. As used in this Agreement, the following terms shall
have the following respective meanings:

         (a)  "AFFILIATE" means, (i) as to Purchaser, any partnerships, firms,
              corporations, entities, individuals, and their successors and
              assigns, wherever located, which together comprise the Andersen
              Consulting worldwide organization whether by virtue of their
              member firm interfirm agreements with Andersen Consulting
              Partners Societe Cooperative or any successor thereto acting to
              coordinate the business of such entities or by virtue of a
              contract with or ownership, direct or indirect, by a member firm
              or otherwise being under control, directly or indirectly, of one
              or more member firms and which are thereby deemed part of the
              Andersen Consulting worldwide organization and, (ii) as to Kana,
              a legal entity that, directly or indirectly through one or more
              intermediaries, controls, is controlled by, or is under common
              control with Kana. For this purpose "control" shall mean direct
              or indirect beneficial ownership of fifty percent (50%) or more
              of the voting or income interest in such corporation or other
              business entity.

         (b)  "ALLIANCE AGREEMENT" shall mean the Restated Master Alliance
              Agreement by and between the parties hereto of even date herewith.

         (c)  "CLOSING DATE" means the date of the Closing.


<PAGE>

         (d)  "CONSULTING SERVICES AGREEMENT" shall mean the Consulting Services
              Agreement by and between the parties hereto of even date herewith.

         (e)  "EXCHANGE ACT" means the Securities Exchange Act of 1934, as
              amended, and all of the rules and regulations promulgated
              thereunder.

         (f)  "SEC" shall mean the United States Securities and Exchange
              Commission.

         (g)  "SEC DOCUMENTS" shall mean all documents filed by the Company with
              the SEC (including documents filed by Silknet Software, Inc.).

         (h)  "SECURITIES ACT" shall mean the Securities Act of 1933, as
              amended, and all of the rules and regulations promulgated
              thereunder.

         2.   PURCHASE AND SALE OF THE SECURITIES.

              2.1   PURCHASE AND SALE.

         Subject to and upon the terms and conditions set forth in this
Agreement (including all exhibits hereto) and the Alliance Agreement, the
Company agrees to issue and sell to Purchaser, and Purchaser, hereby agrees to
purchase from the Company, at the Closing:

         (a)  400,000 shares of Common Stock; and

         (b)  the Warrant in substantially the form attached hereto as
EXHIBIT B.

         Purchaser shall deliver the consideration as set forth on EXHIBIT A at
the Closing.

              2.2   CLOSING. The closing of the transactions contemplated under
this Agreement (the "Closing") shall take place at the offices of the Company,
740 Bay Road, Redwood City, California, on the second business day after the
Company shall have given written notice to (the "Closing Notice") the Purchaser
that all of the conditions precedent set forth in Section 6.1 have been
satisfied in full or at such other location, date and time as may be agreed upon
between the Purchaser and the Company. At the Closing, the Company shall deliver
to each Purchaser a single stock certificate, registered in the name of such
Purchaser, representing the number of shares of Common Stock purchased by such
Purchaser, and the Warrant, against delivery of the purchase price.

         3.   REPRESENTATIONS AND WARRANTIES OF THE COMPANY.  The Company hereby
represents and warrants to the Purchaser as follows:

              3.1   INCORPORATION. The Company is a corporation duly organized,
validly existing and in good standing under the laws of the State of Delaware
and is qualified to do business in each jurisdiction in which the character of
its properties or the nature of its business requires such qualification, except
where the failure to so qualify would not have a material adverse effect upon
the Company. The Company has all requisite corporate power and authority to
carry on its business as now conducted.


                                       2
<PAGE>

              3.2   CAPITALIZATION. The authorized capital stock of the Company
consists of (i) One billion shares of Common Stock, of which 93,162,339 shares
were outstanding as of June 30, 2000 and (ii) 5,000,000 shares of preferred
stock, of which no shares are outstanding on the date hereof. Except for options
for the purchase of Common Stock or the right to purchase Common Stock pursuant
to the Warrant, the Company's stock option plans and the Company's Employee
Stock Purchase Plan, or as set forth in the SEC Documents, there are no existing
options, warrants, calls, preemptive (or similar) rights, subscriptions or other
rights, agreements, arrangements or commitments of any character obligating the
Company to issue, transfer or sell, or cause to be issued, transferred or sold,
any shares of the capital stock of the Company or other equity interests in the
Company or any securities convertible into or exchangeable for such shares of
capital stock or other equity interests, and there are no outstanding
contractual obligations of the Company to repurchase, redeem or otherwise
acquire any shares of its capital stock or other equity interests except for the
right to repurchase unvested Common Stock purchased by service providers.

              3.3   AUTHORIZATION. All corporate action on the part of the
Company, its officers, directors and stockholders necessary for the
authorization, execution, delivery and performance of this Agreement and the
Warrant and the consummation of the transactions contemplated herein and therein
has been taken. When executed and delivered by the Company, this Agreement shall
constitute the legal, valid and binding obligation of the Company, enforceable
against the Company in accordance with its terms, except as such may be limited
by bankruptcy, insolvency, reorganization or other laws affecting creditors'
rights generally and by general equitable principles. The Company has all
requisite corporate power to enter into this Agreement and to carry out and
perform its obligations under the terms of this Agreement.

              3.4   VALID ISSUANCE OF THE SHARES. The Shares being purchased by
the Purchaser hereunder will, upon issuance pursuant to the terms hereof, and
the Company's Amended and Restated Certificate of Incorporation, be duly
authorized and validly issued, fully paid and nonassessable. The Company has
reserved the Warrant Shares for issuance upon valid exercise of the Warrant, and
upon issuance and payment therefore by cash or otherwise pursuant to the terms
of the Warrant, and the Company's Amended and Restated Certificate of
Incorporation, the Warrant Shares will be duly authorized and validly issued,
fully paid and nonassessable. There are no statutory or contractual
shareholders' preemptive rights or rights of first refusal with respect to the
issuance of the Shares or Warrant Shares.

              3.5   SEC DOCUMENTS. As of their respective filing dates, the SEC
Documents complied in all material respects with the requirements of the
Exchange Act or the Securities Act, as applicable, and none of the SEC Documents
contained any untrue statement of a material fact or omitted to state a material
fact required to be stated therein or necessary in order to make the statements
made therein, in light of the circumstances under which they were made, not
misleading, as of their respective filing dates, except to the extent corrected
by a subsequently filed SEC Document. Except as disclosed in the SEC Documents,
there are no actions, suits, arbitrations, proceedings or investigations
pending, or to the Company's knowledge, threatened involving the Company, or any
other events which could have a material adverse effect on the Company. As of
their respective dates, the financial statements included in the SEC Documents
complied as to form in all material respects with applicable accounting
requirements and with the published rules and regulations of the SEC and NASDAQ
with respect


                                       3
<PAGE>

thereto, and were in accordance with the books and records of the Company, were
complete and accurate in all material respects, and present fairly the
consolidated financial position and results of operations, changes in
stockholders' equity and cash flows of the Company and its subsidiaries as of
the dates and for the periods indicated, in accordance with GAAP, except that
the unaudited financial statements may not be in accordance with GAPP because of
the absence of footnotes normally contained therein and are subject to normal
year end adjustments.

              3.6   CONSENTS. All consents, approvals, orders and authorizations
required on the part of the Company in connection with the execution, delivery
or performance of this Agreement (the "Consents") and the consummation of the
transactions contemplated herein and therein have been obtained and will be
effective as of the Closing Date, except if the failure to obtain such Consents
would not have a material adverse effect on the transactions contemplated
hereby.

              3.7   NO CONFLICT. The execution and delivery of this Agreement by
the Company and the consummation of the transactions contemplated hereby and
thereby will not conflict with or result in any violation of or default (with or
without notice or lapse of time, or both) under, or give rise to a right of
termination, cancellation or acceleration of any obligation or to a loss of a
material benefit under (i) any provision of the Certificate of Incorporation or
By-laws of the Company or (ii) any agreement or instrument, permit, franchise,
license, judgment, order, statute, law, ordinance, rule or regulations,
applicable to the Company or its respective properties or assets.


              3.8   BROKERS OR FINDERS. The Company has not entered into an
agreement with any broker or finder in connection with the transactions
contemplated by this Agreement, and the Company has not incurred, directly or
indirectly, any liability for any brokerage or finders' fees or agents
commissions or any similar charges in connection with this Agreement or any
transaction contemplated hereby.

              3.9   NASDAQ NATIONAL MARKET. The Common Stock is listed on the
Nasdaq National Market System, and there are no pending, or to the Company's
knowledge, threatened proceedings to revoke or suspend such listing.

         4.   REPRESENTATIONS AND WARRANTIES OF THE PURCHASER.  Purchaser
represents and warrants to the Company as follows:

              4.1   AUTHORIZATION. All action on the part of Purchaser and, if
applicable, its officers, directors and shareholders necessary for the
authorization, execution, delivery and performance of this Agreement and the
consummation of the transactions contemplated herein and therein has been taken.
When executed and delivered, this Agreement will constitute the legal, valid and
binding obligation of Purchaser, enforceable against Purchaser in accordance
with its terms, except as such may be limited by bankruptcy, insolvency,
reorganization or other laws affecting creditors' rights generally and by
general equitable principles. Purchaser has all requisite corporate power to
enter into this Agreement and to carry out and perform its obligations under the
terms of this Agreement.


                                       4
<PAGE>

              4.2   PURCHASE ENTIRELY FOR OWN ACCOUNT.  Purchaser is acquiring
the Securities for investment, for its own account and not as nominee or agent,
and not for resale or with a view to distribution thereof in violation of the
Securities Act.

              4.3   PURCHASER STATUS; ETC. Purchaser certifies and represents to
the Company that at the time Purchaser acquires any of the Securities, Purchaser
will be an institutional Purchaser that is an "Accredited Investor" as defined
in Rule 501 of Regulation D promulgated under the Securities Act and was not
organized for the purpose of acquiring the Securities. Purchaser's financial
condition is such that it is able to bear the risk of holding the Securities for
an indefinite period of time and the risk of loss of its entire investment.

              4.4   SECURITIES NOT REGISTERED.

         (a)  Purchaser understands that the Securities have not been
registered under the Securities Act, by reason of their issuance by the Company
in a transaction exempt from the registration requirements of the Securities
Act, and that the Securities must continue to be held by Purchaser and not
re-offered, resold, pledged or otherwise transferred unless a subsequent
disposition thereof is registered under the Securities Act or is exempt from
such registration and any such transfer is otherwise made in accordance with
applicable securities laws of any state of the United States. The Purchaser
understands that the exemptions from registration afforded by Rule 144 (the
provisions of which are known to it) promulgated under the Securities Act depend
on the satisfaction of various conditions, and that, if applicable, Rule 144 may
afford the basis for sales only in limited amounts. The Purchaser understands
that neither the Company nor any of its agents makes any representation as to
the availability of Rule 144 or any other exemption under the Securities Act for
the re-offer, resale, pledge or transfer of the Securities.

         (b)  Purchaser further represents that:

              (i)   No offering circular or prospectus will be provided to such
         Purchaser or prepared in connection with the offer and issuance of the
         Securities and that neither the Company or any of its agents has
         provided, and will not be providing, Purchaser with any other material
         regarding the Securities or the Company prepared by the Company or any
         other person. Purchaser has not requested the Company or any of its
         agents to provide Purchaser with any such information.

              (ii)  Except as set forth in Article 3 of this Agreement, neither
         the Company nor any of its agents makes any representation or warranty,
         expressed or implied, as to the accuracy or completeness of the
         information provided or to be provided to Purchaser by the Company,
         and nothing contained in any documents provided to Purchaser is, or
         shall be relied upon as, a promise or representation by the Company or
         any of its agents.

              (iii) An investment in the Securities includes a high degree of
         risk. In making the decision to acquire the Securities, (a) Purchaser
         has such business and financial experience as is required to give
         Purchaser the capacity to protect its own interests in connection
         with the purchase of the Securities, (b) Purchaser has not relied and
         will not rely on any investigation that any person acting on its behalf
         may have conducted with respect to the Securities or the Company and
         (c) such Purchaser will make its own


                                       5
<PAGE>

         investment decision regarding the Securities based on its own knowledge
         and investigation of the Company and the Securities.

              4.5   NO CONFLICT. The execution and delivery of this Agreement by
Purchaser and the consummation of the transactions contemplated hereby and
thereby will not conflict with or result in any violation of or default by
Purchaser (with or without notice or lapse of time, or both) under, or give rise
to a right of termination, cancellation or acceleration of any obligation or to
a loss of a material benefit under (i) any provision of the organizational
documents of Purchaser or (ii) any agreement or instrument, permit, franchise,
license, judgment, order, statute, law, ordinance, rule or regulations,
applicable to such Purchaser or its respective properties or assets.

              4.6   BROKERS.  Purchaser has not retained, utilized or been
represented by any broker or finder in connection with the transactions
contemplated by this Agreement.

              4.7   CONSENTS. All consents, approvals, orders and authorizations
required on the part of Purchaser in connection with the execution, delivery or
performance of this Agreement and the consummation of the transactions
contemplated herein have been obtained and are effective as of the Closing Date.

         5.   COVENANTS.

         The Company shall use commercially reasonable efforts to include the
Shares and the Warrant Shares in a Registration Statement on Form S-3 (the
"Registration Statement") to be filed with the SEC promptly after the Company is
S-3 eligible, and to request acceleration of effectiveness by September 29,
2000. Such Registration Statement will provide for the non-underwritten resale
of the Shares and the Warrant Shares. Company shall use commercially reasonable
efforts to cause the Registration Statement to remain effective until the
earlier of (a) such time all such Shares and Warrant Shares are sold and (b)
such Shares and Warrant Shares are saleable under Rule 144(k). Such registration
shall be subject to the normal terms and conditions used in connection with
resale prospectuses.

         6.   CONDITIONS PRECEDENT.

              6.1   CONDITIONS TO THE OBLIGATION OF THE PURCHASER TO CONSUMMATE
THE CLOSING. The obligation of Purchaser to consummate the Closing and to
purchase and pay for the Securities being purchased by it pursuant to this
Agreement is subject to the satisfaction of the following conditions precedent:

         (a)  The representations and warranties contained herein of
              the Company shall be true and correct on and as of the Closing
              Date with the same force and effect as though made on and as of
              the Closing Date (it being understood and agreed by Purchaser
              that, in the case of any representation and warranty of the
              Company contained herein which is not hereinabove qualified by
              application thereto of a materiality standard, such
              representation and warranty need be true and correct only in all
              material respects in order to satisfy as to such representation
              or warranty the condition precedent set forth in the foregoing
              provisions of this Section 6.1(a)).


                                       6
<PAGE>

         (b)  The Alliance and Consulting Services Agreements shall have
              been executed and delivered by the Company.

         (c)  The Company shall have performed all obligations and conditions
              herein required to be performed or observed by the Company

         (d)  No proceeding challenging this Agreement or the transactions
              contemplated hereby, or seeking to prohibit, alter, prevent or
              materially delay the Closing, shall have been instituted before
              any court, arbitrator or governmental body, agency or official and
              shall be pending.

         (e)  The acquisition of the Securities by the Purchaser shall not be
              prohibited by any law or governmental order or regulation. All
              necessary consents and authorizations of, or registrations,
              declarations and filings with, any governmental or administrative
              agency or of any other person with respect to any of the
              transactions contemplated hereby shall have been duly obtained or
              made and shall be in full force and effect.

         (f)  All instruments and corporate proceedings in connection with the
              transactions contemplated by this Agreement to be consummated at
              the Closing shall be satisfactory in form and substance to such
              Purchaser, and such Purchaser shall have received copies (executed
              or certified, as may be appropriate) of all documents which such
              Purchaser may have reasonably requested in connection with such
              transactions.

              6.2   CONDITIONS TO THE OBLIGATION OF THE COMPANY TO
CONSUMMATE THE CLOSING. The obligation of the Company to consummate the Closing
and to issue and sell to Purchaser the Securities to be purchased by it at the
Closing is subject to the satisfaction of the following conditions precedent:

         (a)  The representations and warranties contained herein of
              such Purchaser shall be true and correct on and as of the Closing
              Date with the same force and effect as though made on and as of
              the Closing Date (it being understood and agreed by the Company
              that, in the case of any representation and warranty of Purchaser
              contained herein which is not hereinabove qualified by
              application thereto of a materiality standard, such
              representation and warranty need be true and correct only in all
              material respects in order to satisfy as to such representation
              or warranty the condition precedent set forth in the foregoing
              provisions of this Section 6.2(a)).

         (b)  The Alliance and Consulting Services Agreements shall have been
              executed and delivered by Purchaser.

         (c)  The Purchaser shall have performed all obligations and conditions
              herein required to be performed or observed by the Purchaser on or
              prior to the Closing Date.

         (d)  No proceeding challenging this Agreement or the transactions
              contemplated hereby, or seeking to prohibit, alter, prevent or
              materially delay the Closing, shall


                                       7
<PAGE>

              have been instituted before any court, arbitrator or governmental
              body, agency or official and shall be pending.

         (e)  The issuance of the Securities by the Company shall not be
              prohibited by any law or governmental order or regulation. All
              necessary consents and authorizations of, or registrations,
              declarations and filings with, any governmental or administrative
              agency or of any other person with respect to any of the
              transactions contemplated hereby shall have been duly obtained or
              made and shall be in full force and effect.

         (f)  All instruments and corporate proceedings in connection with the
              transactions contemplated by this Agreement to be consummated at
              the Closing shall be satisfactory in form and substance to the
              Company, and the Company shall have received counterpart
              originals, or certified or other copies of all documents,
              including without limitation records of corporate or other
              proceedings, which it may have reasonably requested in connection
              therewith.

              Transfer, Legends.

              6.3   SECURITIES LAW TRANSFER RESTRICTIONS. Purchaser shall not
sell, assign, pledge, transfer or otherwise dispose or encumber any of the
Shares or Warrant Shares being purchased by it hereunder, except (i) pursuant to
an effective registration statement under the Securities Act, (ii) pursuant to
Rule 144 promulgated under the Securities Act or (iii) pursuant to an available
exemption from registration under the Securities Act and applicable state
securities laws and, if requested by the Company, upon delivery by Purchaser of
an opinion of counsel reasonably satisfactory to the Company to the effect that
the proposed transfer is exempt from registration under the Securities Act and
applicable state securities laws. The Warrant shall not be transferable, except
as explicitly set forth in the Warrant. The Company shall not register on its
securities ledger any transfer of the Securities in violation of this Section.
The Company may, and may instruct any transfer agent for the Company, to place
such stop transfer orders as may be required on the transfer books of the
Company in order to ensure compliance with the provisions of this Section. The
foregoing shall not be deemed a restriction on Purchaser's ability to assign or
transfer the Shares or Warrant Shares to its Affiliates; provided that any
transfer shall be subject to all restrictions set forth above except that the
Company agrees not to request an opinion of counsel, including the imposition of
Legends on any certificate evidencing the transferred Shares as described in
Section 7.2 below.

              6.4   LEGENDS. Each certificate requesting any of the Shares or
Warrant Shares shall be endorsed with the legends set forth below, and Purchaser
covenants that, except to the extent such restrictions are waived by the
Company, it shall not transfer the shares represented by any such certificate
without complying with the restrictions on transfer described in this Agreement
and the legends endorsed on such certificate:

         "THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN
         REGISTERED UNDER THE SECURITIES ACT OF 1933 AND MAY NOT BE OFFERED,
         SOLD, ASSIGNED, PLEDGED, TRANSFERRED OR OTHERWISE DISPOSED OF IN THE
         ABSENCE OF AN EFFECTIVE


                                       8
<PAGE>

         REGISTRATION STATEMENT UNDER SAID ACT OR PURSUANT TO AN AVAILABLE
         EXEMPTION FROM REGISTRATION UNDER SAID ACT. THE COMPANY MAY REQUIRE
         DELIVERY OF AN OPINION OF COUNSEL REASONABLY SATISFACTORY TO THE
         COMPANY THAT ANY PROPOSED TRANSFER IS EXEMPT FROM OR IN COMPLIANCE
         WITH SAID ACT AND ANY APPLICABLE STATE SECURITIES LAW."

         7.   TERMINATION; LIABILITIES CONSEQUENT THEREON.  This Agreement may
be terminated and the transactions contemplated hereunder abandoned at any time
prior to the Closing only as follows:

              (a)   by the Purchaser, upon notice to the Company if the
conditions set forth in Section 6.1 shall not have been satisfied on or prior to
October 15, 2000; or

              (b)   by the Company, upon notice to the Purchaser if the
conditions set forth in Section 6.2 shall not have been satisfied on or prior to
October 15, 2000; or

              (c)   at any time by mutual agreement of the Company and the
Purchaser; or

              (d)   by the Purchaser, if there has been any breach of
any representation or warranty or any material breach of any covenant of the
Company contained herein and the same has not been cured within 15 days after
notice thereof, (it being understood and agreed by Purchaser that, in the case
of any representation or warranty of the Company contained herein which is not
hereinabove qualified by application thereto of a materiality standard, such
representation or warranty will be deemed to have been breached for purposes of
this Section 8.1(d) only if such representation or warranty was not true and
correct in all material respects at the time such representation or warranty was
made by the Company); or

              (e)   by the Company, if there has been any breach of any
representation, warranty or any material breach of any covenant of Purchaser
contained herein and the same has not been cured within 15 days after notice
thereof (it being understood and agreed by the Company that, in the case of any
representation and warranty of the Purchaser contained herein which is not
hereinabove qualified by application thereto of a materiality standard, such
representation or warranty will be deemed to have been breached for purposes of
this Section 8.1(e) only if such representation or warranty was not true and
correct in all material respects at the time such representation or warranty was
made by such Purchaser).

         Any termination pursuant to this Section 8 shall be without liability
on the part of any party, unless such termination is the result of a material
breach of this Agreement by a party to this Agreement in which case such
breaching party shall remain liable for such breach notwithstanding any
termination of this Agreement.

         8.   MISCELLANEOUS PROVISIONS.

              8.1   PUBLIC STATEMENTS OR RELEASES. None of the parties to this
Agreement shall make, issue, or release any announcement, whether to the public
generally, or to any of its suppliers or customers, with respect to this


                                       9

<PAGE>

Agreement or the transactions provided for herein, or make any statement or
acknowledgment of the existence of, or reveal the status of, this Agreement or
the transactions provided for herein, without the prior consent of the other
parties; provided, that nothing in this Section 9.1 shall prevent any of the
parties hereto from making such public announcements as it may consider
necessary in order to satisfy its legal obligations, but to the extent not
inconsistent with such obligations, it shall provide the other parties with an
opportunity to review and comment on any proposed public announcement before it
is made.

              8.2   FURTHER ASSURANCES. Each party agrees to cooperate fully
with the other party and to execute such further instruments, documents and
agreements and to give such further written assurances, as may be reasonably
requested by the other party to better evidence and reflect the transactions
described herein and contemplated hereby, and to carry into effect the intents
and purposes of this Agreement.

              8.3   RIGHTS CUMULATIVE. Each and all of the various rights,
powers and remedies of the parties shall be considered to be cumulative with and
in addition to any other rights, powers and remedies which such parties may have
at law or in equity in the event of the breach of any of the terms of this
Agreement. The exercise or partial exercise of any right, power or remedy shall
neither constitute the exclusive election thereof nor the waiver of any other
right, power or remedy available to such party.

              8.4   PRONOUNS. All pronouns or any variation thereof shall be
deemed to refer to the masculine, feminine or neuter, singular or plural, as the
identity of the person, persons, entity or entities may require.

              8.5   NOTICES.  Any notices, reports or other correspondence
(hereinafter collectively referred to as "correspondence") required or permitted
to be given hereunder shall be sent by postage prepaid first class mail, courier
or telecopy or delivered by hand to the party to whom such correspondence is
required or permitted to be given hereunder. The date of giving any notice shall
be the date of its actual receipt.

All correspondence to the Company shall be addressed as follows:

                           Kana Communications, Inc.
                           740 Bay Road
                           Redwood City, CA 94063
                           Attention: General Counsel
                           Telecopier: (650) 474-8507

 with a copy to:

                           Brobeck, Phleger & Harrison LLP
                           Two Embarcadero Place
                           2200 Geng Road
                           Palo Alto, CA 94303
                           Attention: David A. Makarechian, Esq.
                           Telecopier: (650) 496-2885

                  All correspondence to Purchaser shall be sent to Purchaser at
the address set forth below:


                                       10
<PAGE>

                           Andersen Consulting LLP
                           1661 Page Mill Road
                           Palo Alto, California 94304
                           Fax:  (650) 213-2222
                           Attention: General Counsel

With a copy to:

                           Andersen Consulting LLP
                           100 S. Wacker Drive
                           Chicago, Illinois 60606-5300
                           Fax:  (312) 693-7701
                           Attention: Legal Group, Ventures and Alliances

Any entity may change the address to which correspondence to it is to be
addressed by notification as provided for herein.

              8.6   CAPTIONS.  The captions and paragraph headings of this
Agreement are solely for the convenience of reference and shall not affect its
interpretation.

              8.7   SEVERABILITY. Should any part or provision of this
Agreement be held unenforceable or in conflict with the applicable laws or
regulations of any jurisdiction, the invalid or unenforceable part or provisions
shall be replaced with a provision which accomplishes, to the extent possible,
the original business purpose of such part or provision in a valid and
enforceable manner, and the remainder of this Agreement shall remain binding
upon the parties hereto.

              8.8   GOVERNING LAW; INJUNCTIVE RELIEF.

                    (a)  This Agreement shall be governed by and construed in
accordance with the internal and substantive laws of the State of Delaware and
without regard to any conflicts of laws concepts which would apply the
substantive law of some other jurisdiction.

                    (b)  Each of the parties hereto acknowledges and agrees that
damages will not be an adequate remedy for any material breach or violation of
this Agreement if such material breach or violation would cause immediate and
irreparable harm (an "Irreparable Breach"). Accordingly, in the event of a
threatened or ongoing Irreparable Breach, each party hereto shall be entitled to
seek, in any state or federal court in the United States, equitable relief of a
kind appropriate in light of the nature of the ongoing or threatened Irreparable
Breach, which relief may include, without limitation, specific performance or
injunctive relief; PROVIDED, HOWEVER, that if the party bringing such action is
unsuccessful in obtaining the relief sought, the moving party shall pay the
non-moving party's reasonable costs, including attorney's fees, incurred in
connection with defending such action. Such remedies shall not be the parties'
exclusive remedies, but shall be in addition to all other remedies provided in
this Agreement.


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<PAGE>

              8.9   WAIVER. No waiver of any term, provision or condition of
this Agreement, whether by conduct or otherwise, in any one or more instances,
shall be deemed to be, or be construed as, a further or continuing waiver of any
such term, provision or condition or as a waiver of any other term, provision or
condition of this Agreement.

              8.10  EXPENSES.  Each party will bear its own costs and expenses
in connection with this Agreement.


              8.11  ASSIGNMENT. The rights and obligations of the parties hereto
shall inure to the benefit of and shall be binding upon the authorized
successors and permitted assigns of each party. Other than an assignment to an
Affiliate or in the event of a merger, sale of substantially all the assets or
similar change of control (in which case the assigning party shall provide
prompt notice to the other party of the assignment), neither party may assign
its rights or obligations under this Agreement or designate another person (i)
to perform all or part of its obligations under this Agreement or (ii) to have
all or part of its rights and benefits under this Agreement, in each case
without the prior written consent of the other party. In the event of any
assignment in accordance with the terms of this Agreement, the assignee shall
specifically assume and be bound by the provisions of the Agreement by executing
and agreeing to an assumption agreement reasonably acceptable to the other
party.

              8.12  SURVIVAL. The respective representations and warranties
given by the parties hereto shall terminate upon the Closing Date. The other
covenants and agreements contained herein, shall survive the Closing Date and
the consummation of the transactions contemplated herein for a period one year
(unless clearly stated otherwise), without regard to any investigation made by
any party.

              8.13  ENTIRE AGREEMENT. This Agreement (and all exhibits and
agreements referenced herein) constitute the entire agreement between the
parties hereto respecting the subject matter hereof and supersedes all prior
agreements, negotiations, understandings, representations and statements
respecting the subject matter hereof, whether written or oral. No modification,
alteration, waiver or change in any of the terms of this Agreement shall be
valid or binding upon the parties hereto unless made in writing and duly
executed by the Company and the Purchaser.


                        [Remainder of page intentionally blank.]


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         IN WITNESS WHEREOF, the parties hereto have executed this Stock and
Warrant Purchase Agreement as of the day and year first above written.


COMPANY:                               KANA COMMUNICATIONS, INC.



                                       By: /S/ FRANKLIN P. HUANG
                                           --------------------------------
                                       Name:  Franklin P. Huang
                                       Title: Vice President and General Counsel




PURCHASER:                             ANDERSEN CONSULTING LLP



                                       By: /S/ STEPHEN M. LORACK
                                           ---------------------------------
                                           Name:  Stephen M. Lorack
                                           Title: Partner


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<PAGE>


                                    EXHIBIT A

                                    PURCHASER

                           NUMBER OF SHARES
PURCHASER                  TO BE PURCHASED                        CONSIDERATION
---------                  ----------------                       -------------
Andersen Consulting LLP    400,000                                          (1)




Andersen Consulting LLP    Warrant for 725,000 shares of Common Stock       (1)



(1)  Purchaser's agreements under the Alliance Agreement, including, without
     limitation, all Exhibits thereto.


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<PAGE>

                                    EXHIBIT B

                                     WARRANT











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