CVE-2025-21764
Published: 27 February 2025
Description
In the Linux kernel, the following vulnerability has been resolved: ndisc: use RCU protection in ndisc_alloc_skb() ndisc_alloc_skb() can be called without RTNL or RCU being held. Add RCU protection to avoid possible UAF.
Security Summary
CVE-2025-21764 is a use-after-free (UAF) vulnerability, classified under CWE-416, in the Linux kernel's ndisc_alloc_skb() function within the Neighbor Discovery for IPv6 (ndisc) component. The issue arises because ndisc_alloc_skb() can be invoked without the required RTNL or RCU protection, potentially leading to a UAF condition. It has a CVSS v3.1 base score of 7.8 (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H), indicating high severity due to its potential for significant impact.
A local attacker with low privileges can exploit this vulnerability with low complexity and no user interaction required. Successful exploitation could result in high impacts to confidentiality, integrity, and availability, such as arbitrary code execution, privilege escalation, or kernel crashes leading to denial of service.
Mitigation involves applying the upstream patches provided in the referenced stable kernel commits, including 3c2d705f5adf5d860aaef90cb4211c0fde2ba66d, 628e6d18930bbd21f2d4562228afe27694f66da9, 96fc896d0e5b37c12808df797397fb16f3080879, 9e0ec817eb41a55327a46cd3ce331a9868d60304, and b870256dd2a5648d5ed2f22316b3ac29a7e5ed63, which add RCU protection to ndisc_alloc_skb() to prevent the UAF. Security practitioners should update affected Linux kernel versions to incorporate these fixes.
Details
- CWE(s)