CVE-2025-21638

Updated: 2026-02-27 02:04:11.827157

Description:

In the Linux kernel, the following vulnerability has been resolved: sctp: sysctl: auth_enable: 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.


Links NIST CIRCL RHEL Ubuntu

Severity

Severity Score
CVSS Version 2.x 0.0
CVSS Version 3.x MEDIUM 5.5

Status

OS name Project name Version Score Severity Status Errata Last updated

Statement

AlmaLinux 9.2 ESU kernel 5.14.0 5.5 MEDIUM Ignored 2025-03-02 21:45:17 CVE-2025-21638 is a local-only flaw in the SCTP sysctl handler that can trigger a NULL-pointer deref...
CentOS 8.4 ELS kernel 4.18.0 5.5 MEDIUM Ignored 2025-03-02 21:45:17 Ignored due to low severity
CentOS 8.5 ELS kernel 4.18.0 5.5 MEDIUM Ignored 2025-03-02 21:45:17 Ignored due to low severity
CentOS Stream 8 ELS kernel 4.18.0 5.5 MEDIUM Ignored 2025-03-02 21:45:17 Ignored due to low severity
Oracle Linux 7 ELS kernel-uek 5.4.17 5.5 MEDIUM Ignored 2025-12-04 17:12:19 CVE-2025-21638 is a local-only NULL pointer dereference in the SCTP auth_enable sysctl handler that ...
TuxCare 9.6 ESU kernel 5.14.0 5.5 MEDIUM Ignored 2025-07-05 02:18:11 This flaw is a local-only NULL-pointer dereference in the SCTP sysctl auth_enable path that impacts ...
Ubuntu 16.04 ELS linux-hwe 4.15.0 5.5 MEDIUM Released CLSA-2025:1757965001 2025-09-16 01:45:36 Ignored due to low severity
Ubuntu 16.04 ELS linux 4.4.0 5.5 MEDIUM Released CLSA-2025:1758009836 2025-09-16 12:28:06 Ignored due to low severity
Ubuntu 18.04 ELS linux 4.15.0 5.5 MEDIUM Released CLSA-2025:1758010922 2025-09-16 12:28:08
Ubuntu 20.04 ELS linux 5.4.0 5.5 MEDIUM Ignored 2025-06-24 00:42:04 Ignored due to low severity