{"id":"CVE-2024-43882","revision":"a2e8c38321894a6b9582568d376cb661","records":[{"revision":"a2e8c38321894a6b9582568d376cb661","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2024-43882","aliases":[],"title":"exec: Fix ToCToU between perm check and set-uid/gid usage","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nexec: Fix ToCToU between perm check and set-uid/gid usage\n\nWhen opening a file for exec via do_filp_open(), permission checking is\ndone against the file's metadata at that moment, and on success, a file\npointer is passed back. Much later in the execve() code path, the file\nmetadata (specifically mode, uid, and gid) is used to determine if/how\nto set the uid and gid. However, those values may have changed since the\npermissions check, meaning the execution may gain unintended privileges.\n\nFor example, if a file could change permissions from executable and not\nset-id:\n\n---------x 1 root root 16048 Aug 7 13:16 target\n\nto set-id and non-executable:\n\n---S------ 1 root root 16048 Aug 7 13:16 target\n\nit is possible to gain root privileges when execution should have been\ndisallowed.\n\nWhile this race condition is rare in real-world scenarios, it has been\nobserved (and proven exploitable) when package managers are updating\nthe setuid bits of installed programs. Such files start with being\nworld-executable but then are adjusted to be group-exec with a set-uid\nbit. For example, \"chmod o-x,u+s target\" makes \"target\" executable only\nby uid \"root\" and gid \"cdrom\", while also becoming setuid-root:\n\n-rwxr-xr-x 1 root cdrom 16048 Aug 7 13:16 target\n\nbecomes:\n\n-rwsr-xr-- 1 root cdrom 16048 Aug 7 13:16 target\n\nBut racing the chmod means users without group \"cdrom\" membership can\nget the permission to execute \"target\" just before the chmod, and when\nthe chmod finishes, the exec reaches brpm_fill_uid(), and performs the\nsetuid to root, violating the expressed authorization of \"only cdrom\ngroup members can setuid to root\".\n\nRe-check that we still have execute permissions in case the metadata\nhas changed. It would be better to keep a copy from the perm-check time,\nbut until we can do that refactoring, the least-bad option is to do a\nfull inode_permission() call (under inode lock). It is understood that\nthis is safe against dead-locks, but hardly optimal.","state":0,"publishedAt":"2024-08-21T00:10:49.556+00:00","modifiedAt":"2026-10-15T00:48:49.093+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"product\": \"Linux\",\n \"vendor\": \"Linux\",\n \"defaultStatus\": \"unaffected\",\n \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n \"programFiles\": [\n \"fs/exec.c\"\n ],\n \"versions\": [\n {\n \"version\": \"9167b0b9a0ab7907191523f5a0528e3b9c288e21\",\n \"lessThan\": \"d5c3c7e26275a2d83b894d30f7582a42853a958f\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"9167b0b9a0ab7907191523f5a0528e3b9c288e21\",\n \"lessThan\": \"368f6985d46657b8b466a421dddcacd4051f7ada\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"9167b0b9a0ab7907191523f5a0528e3b9c288e21\",\n \"lessThan\": \"15469d46ba34559bfe7e3de6659115778c624759\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"9167b0b9a0ab7907191523f5a0528e3b9c288e21\",\n \"lessThan\": \"9b424c5d4130d56312e2a3be17efb0928fec4d64\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"9167b0b9a0ab7907191523f5a0528e3b9c288e21\",\n \"lessThan\": \"f6cfc6bcfd5e1cf76115b6450516ea4c99897ae1\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"9167b0b9a0ab7907191523f5a0528e3b9c288e21\",\n \"lessThan\": \"d2a2a4714d80d09b0f8eb6438ab4224690b7121e\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"9167b0b9a0ab7907191523f5a0528e3b9c288e21\",\n \"lessThan\": \"90dfbba89ad4f0d9c9744ecbb1adac4aa2ff4f3e\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"9167b0b9a0ab7907191523f5a0528e3b9c288e21\",\n \"lessThan\": \"f50733b45d865f91db90919f8311e2127ce5a0cb\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n }\n ]\n }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"product\": \"Linux\",\n \"vendor\": \"Linux\",\n \"defaultStatus\": \"affected\",\n \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n \"programFiles\": [\n \"fs/exec.c\"\n ],\n \"versions\": [\n {\n \"version\": \"2.6.18\",\n \"status\": \"affected\"\n },\n {\n \"version\": \"0\",\n \"lessThan\": \"2.6.18\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"4.19.320\",\n \"lessThanOrEqual\": \"4.19.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.4.282\",\n \"lessThanOrEqual\": \"5.4.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.10.224\",\n \"lessThanOrEqual\": \"5.10.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.15.165\",\n \"lessThanOrEqual\": \"5.15.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.1.106\",\n \"lessThanOrEqual\": \"6.1.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.6.47\",\n \"lessThanOrEqual\": \"6.6.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.10.6\",\n \"lessThanOrEqual\": \"6.10.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.11\",\n \"lessThanOrEqual\": \"*\",\n \"status\": \"unaffected\",\n \"versionType\": \"original_commit_for_fix\"\n }\n ]\n }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/d5c3c7e26275a2d83b894d30f7582a42853a958f","https://git.kernel.org/stable/c/368f6985d46657b8b466a421dddcacd4051f7ada","https://git.kernel.org/stable/c/15469d46ba34559bfe7e3de6659115778c624759","https://git.kernel.org/stable/c/9b424c5d4130d56312e2a3be17efb0928fec4d64","https://git.kernel.org/stable/c/f6cfc6bcfd5e1cf76115b6450516ea4c99897ae1","https://git.kernel.org/stable/c/d2a2a4714d80d09b0f8eb6438ab4224690b7121e","https://git.kernel.org/stable/c/90dfbba89ad4f0d9c9744ecbb1adac4aa2ff4f3e","https://git.kernel.org/stable/c/f50733b45d865f91db90919f8311e2127ce5a0cb"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2024-43882","license":"CVE Program Terms of Use","key":"cve-program:CVE-2024-43882","identifiers":["CVE-2024-43882"]},"retained":false,"historicalAffected":[]}],"coverage":[]}