CVE-2026-23457
Medium
Elevated severity or exploit probability.
CVSS breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H
| Attack Vector | N | Network |
| Attack Complexity | L | Low |
| Privileges Required | N | None |
| User Interaction | N | None |
| Scope | U | Unchanged |
| Confidentiality | L | Low |
| Integrity | L | Low |
| Availability | H | High |
Timeline
- 2026-04-03 — Published (NVD)
- 2026-07-24 — Last modified (NVD)
Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack_sip: fix Content-Length u32 truncation in sip_help_tcp() sip_help_tcp() parses the SIP Content-Length header with simple_strtoul(), which returns unsigned long, but stores the result in unsigned int clen. On 64-bit systems, values exceeding UINT_MAX are silently truncated before computing the SIP message boundary. For example, Content-Length 4294967328 (2^32 + 32) is truncated to 32, causing the parser to miscalculate where the current message ends. The loop then treats trailing data in the TCP segment as a second SIP message and processes it through the SDP parser. Fix this by changing clen to unsigned long to match the return type of simple_strtoul(), and reject Content-Length values that exceed the remaining TCP payload length.
Affected
References
- https://git.kernel.org/stable/c/528b4509c9dfc272e2e92d811915e5211650d383
- https://git.kernel.org/stable/c/75fcaee5170e7dbbee778927134ef2e9568b4659
- https://git.kernel.org/stable/c/865dba58958c3a86786f89a501971ab0e3ec6ba9
- https://git.kernel.org/stable/c/b75209debb9adab287b3caa982f77788c1e15027
- https://git.kernel.org/stable/c/cd1b7403ec835f8a0b3f1f7e68ac26af2cb1e42f
- https://git.kernel.org/stable/c/d4f17256544cc37f6534a14a27a9dec3540c2015
- https://git.kernel.org/stable/c/ed81b6a7012485acdb9c6c80735a0b7d8e5e1873
- https://git.kernel.org/stable/c/fbce58e719a17aa215c724473fd5baaa4a8dc57c
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html