The overlayfs implementation in the linux kernel did not properly validate with respect to user namespaces the setting of file capabilities on files in an underlying file system. Due to the combination of unprivileged user namespaces along with a patch carried in the Ubuntu kernel to allow unprivileged overlay mounts, an attacker could use this to gain elevated privileges.
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2021-3493.json"
[
{
"digest": {
"threshold": 0.9,
"line_hashes": [
"136222003621751214034347229320246339599",
"327055065265802538785480899733861421542"
]
},
"signature_type": "Line",
"deprecated": false,
"signature_version": "v1",
"source": "https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git@7c03e2cda4a584cadc398e8f6641ca9988a39d52",
"target": {
"file": "include/linux/capability.h"
},
"id": "CVE-2021-3493-19f46aac"
},
{
"digest": {
"threshold": 0.9,
"line_hashes": [
"66464055906217110042715449064538536162",
"113914156510451062757820604007002663236",
"261960956168266207662396202313840396924",
"129851580153906976764896030996596536675",
"206474482113133569494662709900339019610",
"63003482969693534455828377855968929659",
"29416968285375379339551365331221669884",
"56365914608453558854293700494176041919",
"17583419377465549788925645947346411201",
"113482257536269989557526218834402076284",
"181105316899457267309751504034412789573",
"304148462144318381905973019491512865013",
"327258792218495083793897895319635827905",
"112491384123311141742136476890489599971",
"149105034430947717343197454101608278953",
"2962426378337091221464112091144559701",
"90178911305518719174168528156437436203",
"296969181878483049032618808663250883118"
]
},
"signature_type": "Line",
"deprecated": false,
"signature_version": "v1",
"source": "https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git@7c03e2cda4a584cadc398e8f6641ca9988a39d52",
"target": {
"file": "fs/xattr.c"
},
"id": "CVE-2021-3493-2e3a4abc"
},
{
"digest": {
"length": 380.0,
"function_hash": "9624705079761973652858806468842098837"
},
"signature_type": "Function",
"deprecated": false,
"signature_version": "v1",
"source": "https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git@7c03e2cda4a584cadc398e8f6641ca9988a39d52",
"target": {
"file": "fs/xattr.c",
"function": "vfs_setxattr"
},
"id": "CVE-2021-3493-90dc8284"
},
{
"digest": {
"length": 1103.0,
"function_hash": "159105732330686574529093485414401479285"
},
"signature_type": "Function",
"deprecated": false,
"signature_version": "v1",
"source": "https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git@7c03e2cda4a584cadc398e8f6641ca9988a39d52",
"target": {
"file": "security/commoncap.c",
"function": "cap_convert_nscap"
},
"id": "CVE-2021-3493-a58b9f15"
},
{
"digest": {
"threshold": 0.9,
"line_hashes": [
"105120649594388539859121240355633656806",
"92306782188406536994234344657677811003",
"237751863430893606152742872683142300707",
"189137168436457682498721654184817090748",
"108523257872024897858045287360088712045",
"257078722168828275588560185445843800917",
"63431798111867035665435641946090843613",
"256893322856912541490732987393042425113"
]
},
"signature_type": "Line",
"deprecated": false,
"signature_version": "v1",
"source": "https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git@7c03e2cda4a584cadc398e8f6641ca9988a39d52",
"target": {
"file": "security/commoncap.c"
},
"id": "CVE-2021-3493-c3c30a3a"
},
{
"digest": {
"length": 976.0,
"function_hash": "211254096835297478288760196411254402200"
},
"signature_type": "Function",
"deprecated": false,
"signature_version": "v1",
"source": "https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git@7c03e2cda4a584cadc398e8f6641ca9988a39d52",
"target": {
"file": "fs/xattr.c",
"function": "setxattr"
},
"id": "CVE-2021-3493-f5634db5"
}
]