CVE-2025-21637
Medium
Elevated severity or exploit probability.
CVSS breakdown
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
| Attack Vector | L | Local |
| Attack Complexity | L | Low |
| Privileges Required | L | Low |
| User Interaction | N | None |
| Scope | U | Unchanged |
| Confidentiality | N | None |
| Integrity | H | High |
| Availability | H | High |
Timeline
- 2025-01-19 — Published (NVD)
- 2026-07-30 — Last modified (NVD)
Description
In the Linux kernel, the following vulnerability has been resolved: sctp: sysctl: udp_port: avoid using current->nsproxy As mentioned in a previous commit of this series, using the 'net' structure via 'current' is not recommended for different reasons: - Inconsistency: getting info from the reader's/writer's netns vs only from the opener's netns. - current->nsproxy can be NULL in some cases, resulting in an 'Oops' (null-ptr-deref), e.g. when the current task is exiting, as spotted by syzbot [1] using acct(2). The 'net' structure can be obtained from the table->data using container_of(). Note that table->data could also be used directly, but that would increase the size of this fix, while 'sctp.ctl_sock' still needs to be retrieved from 'net' structure.
Affected
References
- https://git.kernel.org/stable/c/0a0966312ac3eedd7f5f2a766ed4702df39a9a65
- https://git.kernel.org/stable/c/55627918febdf9d71107a1e68d1528dc591c9a15
- https://git.kernel.org/stable/c/5b77d73f3be5102720fb685b9e6900e3500e1096
- https://git.kernel.org/stable/c/c10377bbc1972d858eaf0ab366a311b39f8ef1b6
- https://git.kernel.org/stable/c/e919197fb8616331f5dc81e4c3cc3d12769cb725
- https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html