2023/06/30: SE202301: ?????????????:
CVE-2023-27395 ? 6 ?: ? Cisco Systems ?
?????? SoftEther VPN ???????
2023/6/30 ? ??
Related: CVE-2023-27395, CVE-2023-22325, CVE-2023-32275, CVE-2023-27516,
CVE-2023-32634, CVE-2023-31192

SoftEther VPN ?????????????????????????? (?????????????????) ???????????????????

SoftEther VPN ????????2023 ? 4 ??? 6 ???????? Cisco Systems, Inc. ??????????????????
????SoftEther VPN ???????????????????????????
?????????????????????????????????????????????????????????????????????????????????
?????SoftEther VPN ?????740 ??????????????????????????????? VPN ????????????????
?????????????????????????????????????????????????????????????????????????????????
?????????????? ISP ??????????????????????????????????????????????????????????????
??????????????????????????????SoftEther VPN ????????????????????????????????????
??????? ISP ?????????????????????????????????????????????????????????????????????
????????
???????????CVE-2023-27395?CVE-2023-22325?CVE-2023-32275?CVE-2023-27516?
CVE-2023-32634?CVE-2023-31192 ??????????????? Cisco Systems, Inc. ?????
SoftEther VPN ??????????????????????
SoftEther VPN ???????????????????????????????? ?? Cisco Systems, Inc. ??????? Cisco
Talos ??????????????? Lilith ????????????????
SoftEther VPN ??????????????? (Apache 2.0 ?????) ????????????????????????????????
????????????????????????????????????????????????????????????????????????1, 2, 6 ?
??
1. CVE-2023-27395: ????? ISP ???????????????????????????????????????????
SoftEther VPN DDNS ?????????????????????????????????????????????

2. CVE-2023-22325: ????? ISP ???????????????????????????????????????????
SoftEther VPN DDNS ?????????????????????????????
3. CVE-2023-32275: 32bit ? VPN Client ? VPN Server ?????????????? VPN ??????
????? CA ?????????????????????????????
4. CVE-2023-27516: SoftEther VPN Client ???????????????????????????????????
?????????????????? VPN Client ????????????????????????????????????
5. CVE-2023-32634: SoftEther VPN Client ?????????????????????????? VPN
Client ??????????????????? VPN Client ???????? TCP ??????????????????????
???? TCP ?????????????? VPN Client ???????????????????
6. CVE-2023-31192: SoftEther VPN Client ??????? VPN Server ???????????????
(???????) ???????????????????????20 ??????????????????????????
?????????????

1. CVE-2023-27395: ????? ISP ??????????????????????????????????
????????? SoftEther VPN DDNS ????????????????????????????????
?????????????
(1) ???
CVSS v3.1: AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H (8.1)?????????????????????????? DNS (DDNS) ????????? DDNS ???????? TCP ???????????
?????????????????????????????????????????????????????????????????????????????????
??

(2) ??
SoftEther VPN Server / Bridge (????) ?????????????? DNS (DDNS) ?????????????VPN
Server ? DDNS ???????? TCP ??????????????????????????????????VPN Server ???????
??????????????????VPN Server ???????????????????????????????????????????????????
???OS ??????????????????????????????????????????????????????????????????????????
????VPN Server ??????????????

(3) ???????
SoftEther VPN 4.41 Build 9787 RTM ???????
? SoftEther VPN ????????????PacketiX VPN???????????

(4) ?????
?????VPN ??????????????????????????????? (ISP?WiFi ??????) ?????? DNS ??????????
???????? DNS ????????????? DNS ???????? TCP/IP ???????????? DNS ???????????????
????????????????????????????

(5) ??
SoftEther VPN Server ????????? DNS ????????????????????????? DNS ???????????????
?DNS ?????????????????????????????
?????? DNS ???? https://www.softether.net/ ???***.softether.net? (*** ???????????????
?)??????
?? SoftEther VPN Server ??????? DNS ????????????????????????????? (RPC?HTTP ???
?Remote Procedure Call) ???????????????????
???? VPN Server ???????????????? ISP ??????????????????????????????????VPN
Server ??????? DNS ???????? RPC ?????????????? RPC ???????????????
?????RPC ????????????????RPC ????????????????????????????? SoftEther VPN Server????????????????????????????
??????VPN Server ???????????????VPN Server ????????????????VPN Server ?????????
???????????????????????? VPN ???????????????????
???????????????????????VPN ??????? DoS ??????????????
?????????????????????????OS ??? C ???????????????????????????????????????????????
?????????????????????????????????????????????????????????????????????????????????
????????????
?????????????????????????????????????????????? HTTP ?????? DNS ????????? DDNS????????????? SSL ???????????????????

2. CVE-2023-22325: ????? ISP ??????????????????????????????????
????????? SoftEther VPN DDNS ?????????????????????????????
(1) ???
CVSS v3.1: AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H (5.9)

(2) ??
SoftEther VPN Server ?????????????? DNS (DDNS) ?????????????VPN Server ? DDNS???????? TCP ?????????????????????????????????VPN Server ?????? DDNS ??????????
?????????????????VPN Server ?????? DDNS ?????????????????VPN Server ??????????
??????????? IP ???????????????? DDNS ????????????????????????????VPN Server ????
????????????????????????????????

(3) ???????
SoftEther VPN 4.41 Build 9787 RTM ???????
? SoftEther VPN ????????????PacketiX VPN???????????

(4) ?????
?????VPN ??????????????????????????????? (ISP?WiFi ??????) ?????? DNS ??????????
???????? DNS ????????????? DNS ???????? TCP/IP ???????????? DNS ???????????????
????????????????????????????

(5) ??
CVE-2023-27395 ?????????????DDNS ? RPC ??????????????????????????????????????
????? VPN Server ????????????????????????????????? DDNS ?????????????????DDNS???????????????????????DDNS ??????????????????????????????DDNS ??????????????
??????????????????????????????????????????????????????????DDNS ????????????????
????????
????????????????????????????????????????????? HTTP ?????? DNS ????????? DDNS ?
???????????? SSL ???????????????????

3. CVE-2023-32275: 32bit ? VPN Client ? VPN Server ??????????????
VPN ??????????? CA ?????????????????????????????

(1) ???
5.5 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

(2) ??
SoftEther VPN Client ? SoftEther VPN Server ???????????? (CA) ????????????????32bit? SoftEther VPN Client ??? VPN Server ????????????????????????????????????????????
????????????????????? ID ?????????????????????????????????????????????? VPN ????
?????????????????????????????????????????????????????????????
??????????????????? (VPN ???????????????????????????????????????????????????????
??????????????????????) ?????????????????????????????????????????????????????????
?????????????????????????????????????????????????????????????????????????????????
????????????????????
???64bit ? SoftEther VPN ????????????????????????????????????????64bit ???????????
?????????????????????????????????????????????????????????????????????????????????
??????

(3) ???????
SoftEther VPN 4.41 Build 9787 RTM ???????
??? PacketiX VPN 4.41 Build 9787 RTM ???????

(4) ?????
??????????????????????????????? VPN Server ??? VPN Client ???????????????????????
????????????????

(5) ??
???????????32bit ??64bit ?????????????????????????????????????????????????????????
???????????????????????????????????????

4. CVE-2023-27516: SoftEther VPN Client ????????????????????????
????????????????????????????? VPN Client ?????????????????????
???????????????

(1) ???
7.0 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:L

????SoftEther VPN Client ?????????????????????????????????????

(2) ??
SoftEther VPN Client ??VPN Client ????????VPN Client Manager ??? vpncmd ????????
???????? 2 ????????????????? VPN Client Manager ??? vpncmd ????????????????????
TCP ???? RPC ????????????VPN Client ??????? VPN Client Manager ??? vpncmd ?????
???????????????????????????????????????????????? (localhost, 127.0.0.1) ???????????
??
SoftEther VPN Client ??????? VPN Client ?????????????????????? (localhost ??) ??????
????????????????????????????????
??????? VPN Client ?????????????????????????????????????????? VPN Client ???TCP ?
??????????????????????????????????????????????? VPN Client ??????????????????????
????

(3) ???????
SoftEther VPN 4.41 Build 9787 RTM ???????
??? PacketiX VPN 4.41 Build 9787 RTM ???????

(4) ?????
SoftEther VPN Client ???????????????????????????????????????????????????? VPN
Client ?????????????????????????????????????

(5) ??
SoftEther VPN Client ???????????????????????????????????????????????????????????
?????????????????????????????????????????????????????????????????????????????????
?????????????????????????????????????????VPN Client ????????????????????????????
?? 100%?????????????????????????????????????????????????????????????????????????
?????????????????????????????????????????
???????SoftEther VPN Client ?????????????????????????????????????????????????????
??????????????????????????????

5. CVE-2023-32634: SoftEther VPN Client ????????????????????????
?? VPN Client ??????????????????? VPN Client ???????? TCP ??????
???????????????????? TCP ?????????????? VPN Client ???????????
????????

(1) ???
7.8 - CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H(2) ??
SoftEther VPN Client ??VPN Client ????????VPN Client Manager ??? vpncmd ????????
???????? 2 ????????????????? VPN Client Manager ??? vpncmd ????????????????????
TCP ???? RPC ????????????VPN Client ??????? VPN Client Manager ??? vpncmd ?????
???????????????????????????????????????????????? (localhost, 127.0.0.1) ???????????
??
????VPN Client ???????????????????????????????? (?: OS ????????????????) ?????????
?????????????????????????????VPN Client ?????????????????VPN Client ???????? TCP??????????????????????????????VPN Client ????????????????VPN Client ???????? TCP????????????TCP ???????????????????????????????????????????????????????
DynamicPortListener ??????????????? TCP ?????????????? VPN Client Manager ???
TCP RPC ???????DynamicPortListener ????????????? VPN Client ??????????????????
??VPN Client ???????????????????????????????????????????? TCP ??????????????????
???????????????????

(3) ???????
SoftEther VPN 4.41 Build 9787 RTM ???????
??? PacketiX VPN 4.41 Build 9787 RTM ???????

(4) ?????
?????VPN Client ???????????????????????????????????????????????????????????????
??

(5) ??
???????????????????????????????????????????????????????????????????????????????
??????????????????? SSH ??????????????????1 ?????????????????????????????????????
????????????????
???????????????DynamicPortListener ??????/?????????????? VPN Client ??????????
DynamicPortListener ????Windows ?????????????UNIX ????????????????Windows ???
???????????????Windows ? VPN Client ???????????? 1 ?????? 1 ?????????????????????
??UNIX ??????????????????????
DynamicPortListener ?????/????vpn_client.config ?????????
DisableRpcDynamicPortListener ???? true / false ?????????

6. CVE-2023-31192: SoftEther VPN Client ??????? VPN Server ??????
????????? (???????) ???????????????????????20 ?????????????????
?????????

(1) ???
5.3 - CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N(2) ??
??????????????????????????????????????????????
VPN Client (VPN Server / VPN Bridge ?????????????) ? VPN Server ???????VPN
Server ??????????????????????????????????????????????????????????????????????????
?????????????Ticket?????? 20 ?????????????????????????Ticket ?????VPN Client ?????
?????????????????C ?????? 20 ???? UCHAR ticket[20] ??????????????????????????????
??? Ticket ????????????????????????????UCHAR ticket[20] ?????????????????????????
?????????????????
???????VPN Client ?????????????? VPN Server ????????????????????? C ?????? 20 ???
? UCHAR ticket[20] ?????????????? VPN Server ???????????????????????????????????
???????????? 20 ????????????????????? VPN Server ??????????????????? 20 ??????????
?????????

(3) ???????
SoftEther VPN 4.41 Build 9787 RTM ???????

??? PacketiX VPN 4.41 Build 9787 RTM ???????

(4) ?????
??????????????????????????? DNS ?????????????????VPN Client ?????????????? VPN
Server ??????????????????????
???VPN Client ? VPN Server ? SSL ????????????????SSL ?????????????????SSL ?????
???????????????????? VPN Server ????????????

(5) ??
?????????????? VPN Server ??VPN Client ???????????? VPN Client ??????????
UCHAR ticket[20] ??? 20 ?????????????????????
????????????? UCHAR ticket[20] ?????????????????????????????????????????????????
?????????????????????????????????????????????????????????????????????????????????
????????????? (?????for ???? int i, j, k ??????) ??????????????????????????????????????
???????????????????????????????????????????????? 20 ?????????????????????????????
??????????????????????????????C ???????????????????????????????? (????????????) ??
?????????????????????????? 20 ???????????????????????????????????????????????????
?????????????????????????????????????????????????????????????????????????????????
???????????????????????????????

????????????????????
2023/06/30 ?????????????
• VPN 4.42 Build 9798 RTM ???????