Document:

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Exhibit 4.8

                              CYRAS SYSTEMS, INC.

           4 1/2% Convertible Subordinated Notes Due August 15, 2005

                          FIRST SUPPLEMENTAL INDENTURE

                         Dated as of November 27, 2000

                                       to

                                   INDENTURE

                          Dated as of August 18, 2000

            STATE STREET BANK AND TRUST COMPANY OF CALIFORNIA, N.A.

<PAGE>   2

      FIRST SUPPLEMENTAL INDENTURE (the "First Supplemental Indenture") dated as
of November 27, 2000 between Cyras Systems, Inc., a California corporation (the
"Company"), and State Street Bank and Trust Company of California, N.A., a
national banking association organized and existing under the laws of the United
States (the "Trustee").

                              W I T N E S S E T H:

      WHEREAS, there has previously been executed and delivered to the Trustee
an Indenture dated as of August 18, 2000 (the "Indenture"), providing for the
issuance of $150,000,000 in aggregate principal amount of 4 1/2% Convertible
Subordinated Notes due August 15, 2005 (the "Notes") by the Company;

      WHEREAS, Section 4.1 of the Indenture provides that the Notes will not be
convertible prior to the 90th day following a Complying Public Equity Offering;

      WHEREAS, prior to the execution of the Indenture it was the Company's
intent in connection with the Company's contemplated Complying Public Equity
Offering to reincorporate the Company from California to Delaware by merging
(the "Merger") Cyras Systems California with and into Cyras Systems, Inc., a
Delaware corporation ("Cyras Systems Delaware"), with Cyras Systems Delaware as
the surviving corporation in the Merger pursuant to an Agreement and Plan of
Merger between Cyras Systems California and Cyras Systems Delaware;

      WHEREAS, Section 4.11 of the Indenture provides that in the event of
certain mergers or consolidations occurring prior to Complying Public Equity
Offering the Notes will become convertible as a result of such merger or
consolidation at a conversion price of $55.40 per share, subject to the certain
adjustments, notwithstanding the aforementioned provisions of Section 4.11 of
the Indenture;

      WHEREAS, Section 3.8 of the Indenture provides that the reincorporation of
the Company from California to Delaware in contemplation of a Complying Public
Equity Offering will not constitute a Change in Control under the Indenture;

      WHEREAS, the Company now desires to modify the Indenture, as set forth
herein, in order to expressly provide that the reincorporation of the Company
from California and Delaware in preparation for the Company's proposed Complying
Public Equity Offering would not result in Notes being immediately convertible
into Common Stock at the conversion price set forth in Section 4.11;

      WHEREAS, Section 11.1 of the Indenture provides that the Company (as
defined in the Indenture) and the Trustee may, without the consent of any
Holders, enter into a supplemental indenture to cure any inconsistency;

      WHEREAS, in accordance with Section 12.4 of the Indenture, the Company (as
defined in the Indenture) has delivered to the Trustee an Officers' Certificate
and an Opinion of Counsel;

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      WHEREAS, all acts and proceedings required by law, under the Indenture to
constitute this First Supplemental Indenture a valid and binding agreement for
the uses and purposes set forth herein, in accordance with its terms, have been
done and taken, and the execution and delivery of this First Supplemental
Indenture have been in all respects duly authorized by the Company; and

      WHEREAS, the foregoing recitals are made as representations of fact by the
Company and not by the Trustee;

      NOW, THEREFORE, in consideration of the foregoing and for other good and
valuable consideration, the receipt of which is hereby acknowledged, the Company
and the Trustee hereby agree as follows:

      1.    For the purposes of this First Supplemental Indenture, except as
otherwise herein expressly provided or unless the context otherwise requires:
(i) the capitalized terms and expressions used herein shall have the same
meaning as corresponding terms and expressions used in the Indenture; and (ii)
the words "herein," "hereof" and "hereby" and other words of similar import used
in this First Supplemental Indenture refer to this First Supplemental Indenture
as a whole and not to any particular section hereof.

      2.    Effective as of the date hereof, Section 4.11 is amended by adding
the following sentence to the end of the first paragraph of Section 4.11:

            Notwithstanding the foregoing provisions of this Section 4.11, in no
event will the Notes become convertible on or prior to a Complying Public Equity
Offering as a result of a merger or consolidation that involves the
reincorporation of the Company from a California corporation to a Delaware
corporation in contemplation of a Complying Public Equity Offering.

      3.    The Trustee accepts the amendment of the Indenture effected by this
First Supplemental Indenture and agrees to execute the trust created by the
Indenture, as hereby amended, including the terms and conditions as set forth in
the Indenture, as hereby amended, including the terms and provisions defining
and limiting the liabilities and responsibilities of the Trustee, which terms
and provisions shall in like manner define and limit its liabilities in the
performance of the trust created by the Indenture, as hereby amended, and
without limiting the generality of the foregoing, the Trustee has no
responsibility for the correctness of the recitals of fact herein contained
which shall be taken as the statements of the Company and makes no
representations as to the validity or sufficiency of this First Supplemental
Indenture and shall incur no liability or responsibility in respect of the
validity thereof.

      4.    Except as expressly amended hereby, the Indenture is in all respects
ratified and confirmed, and all the terms, conditions and provisions hereof
shall remain in full force and effect.

      5.    This First Supplemental Indenture shall form a part of the Indenture
for all purposes, and every holder of Notes heretofore or hereafter
authenticated shall be bound hereby.

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      6.    This First Supplemental Indenture may be executed in any number of
counterparts, each of which when so executed shall be deemed to be an original,
and all of such counterparts shall together constitute one and the same
instrument.

      7.    This First Supplemental Indenture shall be deemed to be a contract
made under the laws of the State of New York and for all purposes shall be
governed by and construed in accordance with such laws.

      IN WITNESS WHEREOF, the parties hereto have caused this First Supplemental
Indenture to be duly executed all as of the day and year first above written.

                            CYRAS SYSTEMS, INC.,
                                               =
                            a California corporation

                            By:       _/s/ SHEKHAR MANDAL
                                -----------------------------------------
                                  Shekhar Mandal
                                  Vice President for Finance and Administration
                                  and Chief Financial Officer

                            STATE STREET BANK AND TRUST
                            COMPANY OF CALIFORNIA, N.A.,

                            By:       /s/ STEPHEN RIVERO
                                -----------------------------------------
                                  Stephen Rivero
                                  Vice President

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Exhibit 4.9

                               CYRAS SYSTEMS, INC.

            4 1/2% Convertible Subordinated Notes Due August 15, 2005

                          SECOND SUPPLEMENTAL INDENTURE

                          Dated as of November 28, 2000

                                       to

                                    INDENTURE

                           Dated as of August 18, 2000

             STATE STREET BANK AND TRUST COMPANY OF CALIFORNIA, N.A.

<PAGE>   2

      SECOND SUPPLEMENTAL INDENTURE (the "Second Supplemental Indenture") dated
as of November 28, 2000 between Cyras Systems, Inc., a Delaware corporation
("Cyras Systems Delaware"), and State Street Bank and Trust Company of
California, N.A., a national banking association organized and existing under
the laws of the United States (the "Trustee").

                              W I T N E S S E T H:

      WHEREAS, there has previously been executed and delivered to the Trustee
an Indenture dated as of August 18, 2000 (the "Indenture"), providing for the
issuance of $150,000,000 in aggregate principal amount of 4 1/2% Convertible
Subordinated Notes due August 15, 2005 (the "Notes") of Cyras Systems, Inc., a
California corporation ("Cyras Systems California");

      WHEREAS, Cyras Systems California has merged (or will merge substantially
concurrently with the execution and delivery of this Second Supplemental
Indenture) with and into Cyras Systems Delaware (the "Merger"), with Cyras
Systems Delaware as the surviving corporation in the Merger pursuant to an
Agreement and Plan of Merger, dated as of November 16, 2000, among Cyras Systems
California and Cyras Systems Delaware;

      WHEREAS, pursuant to the Merger each outstanding share of common stock of
Cyras Systems California is converted into one outstanding share of common stock
of Cyras Systems Delaware;

      WHEREAS, in the case of a merger of Cyras Systems California with and into
any other corporation, Article 7 and Section 4.11 of the Indenture require that
the surviving corporation execute and deliver to the Trustee a supplemental
indenture providing for certain conversion rights to Holders of the Notes and
the assumption by the surviving corporation of the covenants, agreements and
obligations of the Company under the Indenture;

      WHEREAS, Section 11.1 of the Indenture provides that the Company (as
defined in the Indenture) and the Trustee may, without the consent of any
Holders, enter into a supplemental indenture to comply with the terms of Article
7 and Section 4.11 of the Indenture;

      WHEREAS, in accordance with Sections 11.1 and 12.4 of the Indenture, the
Company (as defined in the Indenture) has delivered to the Trustee an Officers'
Certificate and an Opinion of Counsel; and

      WHEREAS, all acts and proceedings required by law, under the Indenture and
by the Certificate of Incorporation of Cyras Systems Delaware to constitute this
Second Supplemental Indenture a valid and binding agreement for the uses and
purposes set forth herein, in accordance with its terms, have been done and
taken, and the execution and delivery of this Second Supplemental Indenture have
been in all respects duly authorized by Cyras Systems Delaware;

<PAGE>   3

      NOW, THEREFORE, in consideration of the foregoing and for other good and
valuable consideration, the receipt of which is hereby acknowledged, Cyras
Systems Delaware and the Trustee hereby agree as follows:

      1.    For the purposes of this Second Supplemental Indenture, except as
otherwise herein expressly provided or unless the context otherwise requires:
(i) the capitalized terms and expressions used herein shall have the same
meaning as corresponding terms and expressions used in the Indenture; and (ii)
the words "herein," "hereof" and "hereby" and other words of similar import used
in this Second Supplemental Indenture refer to this Second Supplemental
Indenture as a whole and not to any particular section hereof.

      2.    Cyras Systems Delaware hereby assumes all the covenants, agreements
and obligations of the Company under the Notes and the Indenture, including the
obligation to make due and punctual payment of the principal of and premium, if
any, and interest on all of the Notes and the due and punctual performance of
all of the covenants and conditions to be performed by the Company under the
Indenture. From and after the effective time of the Merger, the Notes shall be
convertible into shares of common stock of Cyras Systems Delaware on the same
terms and basis (and subject to the same adjustments under the Indenture) as the
Notes were convertible into common stock of Cyras Systems California prior to
the effectiveness of the Merger, and on and after the effective time of the
Merger references in the Indenture to "Common Stock" shall be deemed to be
references to common stock of Cyras Systems Delaware.

      3.    The Trustee accepts the amendment of the Indenture effected by this
Second Supplemental Indenture and agrees to execute the trust created by the
Indenture, as hereby amended, including the terms and conditions as set forth in
the Indenture, as hereby amended, including the terms and provisions defining
and limiting the liabilities and responsibilities of the Trustee, which terms
and provisions shall in like manner define and limit its liabilities in the
performance of the trust created by the Indenture, as hereby amended, and
without limiting the generality of the foregoing, the Trustee has no
responsibility for the correctness of the recitals of fact herein contained
which shall be taken as the statements of Cyras Systems Delaware and makes no
representations as to the validity or sufficiency of this Second Supplemental
Indenture and shall incur no liability or responsibility in respect of the
validity thereof.

      4.    Except as expressly amended hereby, the Indenture is in all respects
ratified and confirmed, and all the terms, conditions and provisions hereof
shall remain in full force and effect.

      5.    This Second Supplemental Indenture shall form a part of the
Indenture for all purposes, and every holder of Notes heretofore or hereafter
authenticated shall be bound hereby.

      6.    This Second Supplemental Indenture may be executed in any number of
counterparts, each of which when so executed shall be deemed to be an original,
and all of such counterparts shall together constitute one and the same
instrument.

      7.    This Second Supplemental Indenture shall be deemed to be a contract
made under the laws of the State of New York and for all purposes shall be
governed by and construed in accordance with such laws.

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      IN WITNESS WHEREOF, the parties hereto have caused this Second
Supplemental Indenture to be duly executed all as of the day and year first
above written.

                            CYRAS SYSTEMS, INC.,
                                               =
                            a California corporation

                            By:        /s/ SHEKHAR MANDAL
                                -----------------------------------------
                                  Shekhar Mandal
                                  Vice President for Finance and Administration
                                  and Chief Financial Officer

                            STATE STREET BANK AND TRUST
                            COMPANY OF CALIFORNIA, N.A.,

                            By:       /s/ STEPHEN RIVERO
                                -----------------------------------------
                                  Stephen Rivero
                                  Vice President

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