{ "dataType": "CVE_RECORD", "dataVersion": "5.1", "cveMetadata": { "cveId": "CVE-2024-43882", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-08-17T09:11:59.287Z", "datePublished": "2024-08-21T00:10:49.556Z", "dateUpdated": "2024-09-15T17:54:51.831Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2024-09-15T17:54:51.831Z" }, "descriptions": [ { "lang": "en", "value": "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." } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/exec.c" ], "versions": [ { "version": "1da177e4c3f4", "lessThan": "d5c3c7e26275", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f4", "lessThan": "368f6985d466", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f4", "lessThan": "15469d46ba34", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f4", "lessThan": "9b424c5d4130", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f4", "lessThan": "f6cfc6bcfd5e", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f4", "lessThan": "d2a2a4714d80", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f4", "lessThan": "90dfbba89ad4", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f4", "lessThan": "f50733b45d86", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/exec.c" ], "versions": [ { "version": "4.19.320", "lessThanOrEqual": "4.19.*", "status": "unaffected", "versionType": "custom" }, { "version": "5.4.282", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "custom" }, { "version": "5.10.224", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "custom" }, { "version": "5.15.165", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.1.106", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.6.47", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.10.6", "lessThanOrEqual": "6.10.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.11", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/d5c3c7e26275a2d83b894d30f7582a42853a958f" }, { "url": "https://git.kernel.org/stable/c/368f6985d46657b8b466a421dddcacd4051f7ada" }, { "url": "https://git.kernel.org/stable/c/15469d46ba34559bfe7e3de6659115778c624759" }, { "url": "https://git.kernel.org/stable/c/9b424c5d4130d56312e2a3be17efb0928fec4d64" }, { "url": "https://git.kernel.org/stable/c/f6cfc6bcfd5e1cf76115b6450516ea4c99897ae1" }, { "url": "https://git.kernel.org/stable/c/d2a2a4714d80d09b0f8eb6438ab4224690b7121e" }, { "url": "https://git.kernel.org/stable/c/90dfbba89ad4f0d9c9744ecbb1adac4aa2ff4f3e" }, { "url": "https://git.kernel.org/stable/c/f50733b45d865f91db90919f8311e2127ce5a0cb" } ], "title": "exec: Fix ToCToU between perm check and set-uid/gid usage", "x_generator": { "engine": "bippy-c9c4e1df01b2" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2024-43882", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "version": "2.0.3", "timestamp": "2024-09-10T16:05:44.870893Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-09-12T17:33:06.031Z" } } ] } }