CVE-2023-25136
Published: 3 February 2023
OpenSSH server (sshd) 9.1 introduced a double-free vulnerability during options.kex_algorithms handling. This is fixed in OpenSSH 9.2. The double free can be leveraged, by an unauthenticated remote attacker in the default configuration, to jump to any location in the sshd address space. One third-party report states "remote code execution is theoretically possible."
Notes
| Author | Note |
|---|---|
| seth-arnold | openssh-ssh1 is provided for compatibility with old devices that cannot be upgraded to modern protocols. Thus we may not provide security support for this package if doing so would prevent access to equipment. |
| rodrigo-zaiden | issue introduced in OpenSSH 9.1, hence, not affecting any current Ubuntu releases. The commit that introduced the issue is 486c4dc3b83b4b67d663fb0fa62bc24138ec3946. |
Priority
Status
| Package | Release | Status |
|---|---|---|
|
openssh Launchpad, Ubuntu, Debian |
bionic |
Not vulnerable
(code not present)
|
| focal |
Not vulnerable
(code not present)
|
|
| jammy |
Not vulnerable
(code not present)
|
|
| kinetic |
Not vulnerable
(code not present)
|
|
| lunar |
Not vulnerable
(code not present)
|
|
| mantic |
Not vulnerable
(code not present)
|
|
| noble |
Not vulnerable
(code not present)
|
|
| trusty |
Not vulnerable
(code not present)
|
|
| upstream |
Released
(1:9.2p1-1)
|
|
| xenial |
Not vulnerable
(code not present)
|
|
|
openssh-ssh1 Launchpad, Ubuntu, Debian |
bionic |
Not vulnerable
(code not present)
|
| focal |
Not vulnerable
(code not present)
|
|
| jammy |
Not vulnerable
(code not present)
|
|
| kinetic |
Not vulnerable
(code not present)
|
|
| lunar |
Not vulnerable
(code not present)
|
|
| mantic |
Not vulnerable
(code not present)
|
|
| noble |
Not vulnerable
(code not present)
|
|
| trusty |
Does not exist
|
|
| upstream |
Ignored
(frozen on openssh 7.5p)
|
|
| xenial |
Does not exist
|
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 6.5 |
| Attack vector | Network |
| Attack complexity | High |
| Privileges required | None |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality | None |
| Integrity impact | Low |
| Availability impact | High |
| Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H |