Executive brief
A vulnerability was identified in the Linux kernel's networking subsystem, specifically within the Netfilter component used for firewalling and network address translation (NAT). The flaw involves how the system handles certain types of internet traffic, such as SIP (VoIP) and Amanda backup protocols. An attacker could potentially exploit this to cause a system crash or instability, leading to a denial of service.
Technical details
A stack-based out-of-bounds write vulnerability exists in the Netfilter conntrack/NAT helpers for SIP and Amanda protocols. The root cause is the use of 'sprintf' in 'mangle_content_len' and related functions, which lacks bounds checking when writing to stack-allocated buffers. Specifically, when mangling SIP or SDP content, the buffer size was insufficient to hold the resulting string, leading to a KASAN-detected stack-out-of-bounds error. An attacker can trigger this by sending specially crafted SIP or Amanda packets that require NAT mangling. The issue has been resolved by replacing 'sprintf' with 'scnprintf' and increasing the buffer size in 'mangle_content_len'.
Affected products
- Linux Linux Kernel 2.6.20 to 5.10.258, 6.13.y, 6.14.y
Timeline
- 2026-06-24: advisory: CVE-2026-53002 published by NVD
- 2026-05-23: patched: Fix committed to stable kernel trees
References
- https://git.kernel.org/stable/c/1c9fb8aeed06790d42cdcd00f6c3ce0b9e926c1e
- https://git.kernel.org/stable/c/2f793ba78470a99f40389b7dc60a81d9f5ad3956
- https://git.kernel.org/stable/c/6bbf829b4c1b44c941c47dd0d710f1393258f3d5
- https://git.kernel.org/stable/c/6e7066bdb481a87fe88c4fa563e348c03b2d373d
- https://git.kernel.org/stable/c/8e3be0d12615a173fe260cd42753ca7a001acbf2
- https://git.kernel.org/stable/c/a8e0a32a23d3f34862af3b4da792ecb3a891a9a3
- https://git.kernel.org/stable/c/ab64e61c9323fa6de21bd20da1ddb29a0fb65d34