CVE-2023-25136
Publication date 3 February 2023
Last updated 24 July 2024
Ubuntu priority
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."
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| openssh | 24.04 LTS noble |
Not affected
|
| 22.04 LTS jammy |
Not affected
|
|
| 20.04 LTS focal |
Not affected
|
|
| 18.04 LTS bionic |
Not affected
|
|
| 16.04 LTS xenial |
Not affected
|
|
| 14.04 LTS trusty |
Not affected
|
|
| openssh-ssh1 | 24.04 LTS noble |
Not affected
|
| 22.04 LTS jammy |
Not affected
|
|
| 20.04 LTS focal |
Not affected
|
|
| 18.04 LTS bionic |
Not affected
|
|
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release |
Notes
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.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score |
6.5 · Medium
|
| 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 |