netfilter: nf_conntrack_sip: fix Content-Length u32 truncation in sip_help_tcp()

Summary

CVECVE-2026-23457
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-04-03 16:16:32 UTC
Updated2026-04-18 09:16:28 UTC
DescriptionIn 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.

Risk And Classification

EPSS: 0.000320000 probability, percentile 0.090980000 (date 2026-04-18)

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected f5b321bd37fbec9188feb1f721ab46a5ac0b35da ed81b6a7012485acdb9c6c80735a0b7d8e5e1873 git Not specified
CNA Linux Linux affected f5b321bd37fbec9188feb1f721ab46a5ac0b35da cd1b7403ec835f8a0b3f1f7e68ac26af2cb1e42f git Not specified
CNA Linux Linux affected f5b321bd37fbec9188feb1f721ab46a5ac0b35da b75209debb9adab287b3caa982f77788c1e15027 git Not specified
CNA Linux Linux affected f5b321bd37fbec9188feb1f721ab46a5ac0b35da 528b4509c9dfc272e2e92d811915e5211650d383 git Not specified
CNA Linux Linux affected f5b321bd37fbec9188feb1f721ab46a5ac0b35da 75fcaee5170e7dbbee778927134ef2e9568b4659 git Not specified
CNA Linux Linux affected f5b321bd37fbec9188feb1f721ab46a5ac0b35da 865dba58958c3a86786f89a501971ab0e3ec6ba9 git Not specified
CNA Linux Linux affected f5b321bd37fbec9188feb1f721ab46a5ac0b35da d4f17256544cc37f6534a14a27a9dec3540c2015 git Not specified
CNA Linux Linux affected f5b321bd37fbec9188feb1f721ab46a5ac0b35da fbce58e719a17aa215c724473fd5baaa4a8dc57c git Not specified
CNA Linux Linux affected 2.6.34 Not specified
CNA Linux Linux unaffected 2.6.34 semver Not specified
CNA Linux Linux unaffected 5.10.253 5.10.* semver Not specified
CNA Linux Linux unaffected 5.15.203 5.15.* semver Not specified
CNA Linux Linux unaffected 6.1.167 6.1.* semver Not specified
CNA Linux Linux unaffected 6.6.130 6.6.* semver Not specified
CNA Linux Linux unaffected 6.12.78 6.12.* semver Not specified
CNA Linux Linux unaffected 6.18.20 6.18.* semver Not specified
CNA Linux Linux unaffected 6.19.10 6.19.* semver Not specified
CNA Linux Linux unaffected 7.0 * original_commit_for_fix Not specified

References

ReferenceSourceLinkTags
git.kernel.org/stable/c/d4f17256544cc37f6534a14a27a9dec3540c2015 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/ed81b6a7012485acdb9c6c80735a0b7d8e5e1873 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/b75209debb9adab287b3caa982f77788c1e15027 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/75fcaee5170e7dbbee778927134ef2e9568b4659 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/528b4509c9dfc272e2e92d811915e5211650d383 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/fbce58e719a17aa215c724473fd5baaa4a8dc57c 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/cd1b7403ec835f8a0b3f1f7e68ac26af2cb1e42f 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/865dba58958c3a86786f89a501971ab0e3ec6ba9 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
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