CVE-2026-52986 (GCVE-0-2026-52986)

Vulnerability from cvelistv5 – Published: 2026-06-24 16:29 – Updated: 2026-06-28 06:37
VLAI
Title
netfilter: nf_conntrack_sip: don't use simple_strtoul
Summary
In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack_sip: don't use simple_strtoul Replace unsafe port parsing in epaddr_len(), ct_sip_parse_header_uri(), and ct_sip_parse_request() with a new sip_parse_port() helper that validates each digit against the buffer limit, eliminating the use of simple_strtoul() which assumes NUL-terminated strings. The previous code dereferenced pointers without bounds checks after sip_parse_addr() and relied on simple_strtoul() on non-NUL-terminated skb data. A port that reaches the buffer limit without a trailing character is also rejected as malformed. Also get rid of all simple_strtoul() usage in conntrack, prefer a stricter version instead. There are intentional changes: - Bail out if number is > UINT_MAX and indicate a failure, same for too long sequences. While we do accept 05535 as port 5535, we will not accept e.g. 'sip:10.0.0.1:005060'. While its syntactically valid under RFC 3261, we should restrict this to not waste cycles when presented with malformed packets with 64k '0' characters. - Force base 10 in ct_sip_parse_numerical_param(). This is used to fetch 'expire=' and 'rports='; both are expected to use base-10. - In nf_nat_sip.c, only accept the parsed value if its within the 1k-64k range. - epaddr_len now returns 0 if the port is invalid, as it already does for invalid ip addresses. This is intentional. nf_conntrack_sip performs lots of guesswork to find the right parts of the message to parse. Being stricter could break existing setups. Connection tracking helpers are designed to allow traffic to pass, not to block it. Based on an earlier patch from Jenny Guanni Qu <qguanni@gmail.com>.
Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 05e3ced297fe755093140e7487e292fb7603316e , < 8cd0358379570003659186706e077929d6930c40 (git)
Affected: 05e3ced297fe755093140e7487e292fb7603316e , < 9c6afcb1c3cbb2c0da65b8515ac14d7273872f84 (git)
Affected: 05e3ced297fe755093140e7487e292fb7603316e , < b3264c977e79d8a25778d4fd11520f00fea1329c (git)
Affected: 05e3ced297fe755093140e7487e292fb7603316e , < ea2ecd29b8f4433e52607192ca91084f95787ca0 (git)
Affected: 05e3ced297fe755093140e7487e292fb7603316e , < 9f69c323ae0ab517e595c2cc74e0ae0d9d085611 (git)
Affected: 05e3ced297fe755093140e7487e292fb7603316e , < 7df9863bf538a626e8a684e59cb2c43eac0ef3c8 (git)
Affected: 05e3ced297fe755093140e7487e292fb7603316e , < 523762e3b6933fff81f01dfa3c60c0774044cdab (git)
Affected: 05e3ced297fe755093140e7487e292fb7603316e , < 8cf6809cddcbe301aedfc6b51bcd4944d45795f6 (git)
Create a notification for this product.
Linux Linux Affected: 2.6.26
Unaffected: 0 , < 2.6.26 (semver)
Unaffected: 5.10.258 , ≤ 5.10.* (semver)
Unaffected: 5.15.209 , ≤ 5.15.* (semver)
Unaffected: 6.1.175 , ≤ 6.1.* (semver)
Unaffected: 6.6.141 , ≤ 6.6.* (semver)
Unaffected: 6.12.91 , ≤ 6.12.* (semver)
Unaffected: 6.18.33 , ≤ 6.18.* (semver)
Unaffected: 7.0.10 , ≤ 7.0.* (semver)
Unaffected: 7.1 , ≤ * (original_commit_for_fix)
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_conntrack_sip: don\u0027t use simple_strtoul\n\nReplace unsafe port parsing in epaddr_len(), ct_sip_parse_header_uri(),\nand ct_sip_parse_request() with a new sip_parse_port() helper that\nvalidates each digit against the buffer limit, eliminating the use of\nsimple_strtoul() which assumes NUL-terminated strings.\n\nThe previous code dereferenced pointers without bounds checks after\nsip_parse_addr() and relied on simple_strtoul() on non-NUL-terminated\nskb data. A port that reaches the buffer limit without a trailing\ncharacter is also rejected as malformed.\n\nAlso get rid of all simple_strtoul() usage in conntrack, prefer a\nstricter version instead.  There are intentional changes:\n\n- Bail out if number is \u003e UINT_MAX and indicate a failure, same for\n  too long sequences.\n  While we do accept 05535 as port 5535, we will not accept e.g.\n  \u0027sip:10.0.0.1:005060\u0027.  While its syntactically valid under RFC 3261,\n  we should restrict this to not waste cycles when presented with\n  malformed packets with 64k \u00270\u0027 characters.\n\n- Force base 10 in ct_sip_parse_numerical_param(). This is used to fetch\n  \u0027expire=\u0027 and \u0027rports=\u0027; both are expected to use base-10.\n\n- In nf_nat_sip.c, only accept the parsed value if its within the 1k-64k\n  range.\n\n- epaddr_len now returns 0 if the port is invalid, as it already does\n  for invalid ip addresses.  This is intentional. nf_conntrack_sip\n  performs lots of guesswork to find the right parts of the message\n  to parse.  Being stricter could break existing setups.\n  Connection tracking helpers are designed to allow traffic to\n  pass, not to block it.\n\nBased on an earlier patch from Jenny Guanni Qu \u003cqguanni@gmail.com\u003e."
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This is intentional. nf_conntrack_sip\\n  performs lots of guesswork to find the right parts of the message\\n  to parse.  Being stricter could break existing setups.\\n  Connection tracking helpers are designed to allow traffic to\\n  pass, not to block it.\\n\\nBased on an earlier patch from Jenny Guanni Qu \u003cqguanni@gmail.com\u003e.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"net/netfilter/nf_conntrack_sip.c\",\"net/netfilter/nf_nat_sip.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"05e3ced297fe755093140e7487e292fb7603316e\",\"lessThan\":\"8cd0358379570003659186706e077929d6930c40\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"05e3ced297fe755093140e7487e292fb7603316e\",\"lessThan\":\"9c6afcb1c3cbb2c0da65b8515ac14d7273872f84\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"05e3ced297fe755093140e7487e292fb7603316e\",\"lessThan\":\"b3264c977e79d8a25778d4fd11520f00fea1329c\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"05e3ced297fe755093140e7487e292fb7603316e\",\"lessThan\":\"ea2ecd29b8f4433e52607192ca91084f95787ca0\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"05e3ced297fe755093140e7487e292fb7603316e\",\"lessThan\":\"9f69c323ae0ab517e595c2cc74e0ae0d9d085611\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"05e3ced297fe755093140e7487e292fb7603316e\",\"lessThan\":\"7df9863bf538a626e8a684e59cb2c43eac0ef3c8\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"05e3ced297fe755093140e7487e292fb7603316e\",\"lessThan\":\"523762e3b6933fff81f01dfa3c60c0774044cdab\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"05e3ced297fe755093140e7487e292fb7603316e\",\"lessThan\":\"8cf6809cddcbe301aedfc6b51bcd4944d45795f6\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"net/netfilter/nf_conntrack_sip.c\",\"net/netfilter/nf_nat_sip.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"2.6.26\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"2.6.26\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.10.258\",\"lessThanOrEqual\":\"5.10.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.15.209\",\"lessThanOrEqual\":\"5.15.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.1.175\",\"lessThanOrEqual\":\"6.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.6.141\",\"lessThanOrEqual\":\"6.6.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.91\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.33\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.0.10\",\"lessThanOrEqual\":\"7.0.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":9.8,\"baseSeverity\":\"CRITICAL\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":3.9,\"impactScore\":5.9}]},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/523762e3b6933fff81f01dfa3c60c0774044cdab\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/7df9863bf538a626e8a684e59cb2c43eac0ef3c8\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/8cd0358379570003659186706e077929d6930c40\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/8cf6809cddcbe301aedfc6b51bcd4944d45795f6\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/9c6afcb1c3cbb2c0da65b8515ac14d7273872f84\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/9f69c323ae0ab517e595c2cc74e0ae0d9d085611\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/b3264c977e79d8a25778d4fd11520f00fea1329c\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/ea2ecd29b8f4433e52607192ca91084f95787ca0\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
  }
}


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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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