{"id":"CVE-2025-21637","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: sysctl: udp_port: avoid using current->nsproxy\n\nAs mentioned in a previous commit of this series, using the 'net'\nstructure via 'current' is not recommended for d…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: sysctl: udp_port: avoid using current->nsproxy\n\nAs mentioned in a previous commit of this series, using the 'net'\nstructure via 'current' is not recommended for d…","severity":"high","cvss":7.1,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H","cwe":["CWE-476","CWE-476"],"vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 5.11, < 5.15.177","linux_kernel >= 5.16, < 6.1.125","linux_kernel >= 6.2, < 6.6.72","linux_kernel >= 6.7, < 6.12.10","linux_kernel = 6.13"],"patched":["linux_kernel 6.12.10"],"published":"2025-01-19","updated":"2026-07-30","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2025-21637","references":[{"url":"https://git.kernel.org/stable/c/0a0966312ac3eedd7f5f2a766ed4702df39a9a65","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/55627918febdf9d71107a1e68d1528dc591c9a15","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/5b77d73f3be5102720fb685b9e6900e3500e1096","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c10377bbc1972d858eaf0ab366a311b39f8ef1b6","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e919197fb8616331f5dc81e4c3cc3d12769cb725","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html","label":"af854a3a-2127-422b-91ae-364da2661108"}],"tags":["nvd"],"epss":0.00212,"epssPercentile":0.11739,"ingestedAt":"2026-07-30T06:53:08.824Z","slug":"CVE-2025-21637","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nsctp: sysctl: udp_port: avoid using current->nsproxy\n\nAs mentioned in a previous commit of this series, using the 'net'\nstructure via 'current' is not recommended for different reasons:\n\n- Inconsistency: getting info from the reader's/writer's netns vs only\n  from the opener's netns.\n\n- current->nsproxy can be NULL in some cases, resulting in an 'Oops'\n  (null-ptr-deref), e.g. when the current task is exiting, as spotted by\n  syzbot [1] using acct(2).\n\nThe 'net' structure can be obtained from the table->data using\ncontainer_of().\n\nNote that table->data could also be used directly, but that would\nincrease the size of this fix, while 'sctp.ctl_sock' still needs to be\nretrieved from 'net' structure.\n\n## Affected\n\n- `linux_kernel >= 5.11, < 5.15.177`\n- `linux_kernel >= 5.16, < 6.1.125`\n- `linux_kernel >= 6.2, < 6.6.72`\n- `linux_kernel >= 6.7, < 6.12.10`\n- `linux_kernel = 6.13`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 6.12.10`","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":39.1,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}