Vulnerability Details : CVE-2021-36085
Potential exploit
The CIL compiler in SELinux 3.2 has a use-after-free in __cil_verify_classperms (called from __verify_map_perm_classperms and hashtab_map).
Vulnerability category: Memory Corruption
Products affected by CVE-2021-36085
- cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*
- cpe:2.3:o:selinux_project:selinux:3.2:*:*:*:*:*:*:*
Exploit prediction scoring system (EPSS) score for CVE-2021-36085
0.07%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 28 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2021-36085
Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source | First Seen |
---|---|---|---|---|---|---|
2.1
|
LOW | AV:L/AC:L/Au:N/C:N/I:N/A:P |
3.9
|
2.9
|
NIST | |
3.3
|
LOW | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L |
1.8
|
1.4
|
NIST |
CWE ids for CVE-2021-36085
-
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.Assigned by: nvd@nist.gov (Primary)
References for CVE-2021-36085
-
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/U7ZYR3PIJ75N6U2IONJWCKZ5L2NKJTGR/
[SECURITY] Fedora 35 Update: libsepol-3.3-2.fc35 - package-announce - Fedora Mailing-ListsMailing List;Third Party Advisory
-
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=31124
31124 - selinux:secilc-fuzzer: Heap-use-after-free in __cil_verify_classperms - oss-fuzzExploit;Issue Tracking;Patch;Third Party Advisory
-
https://github.com/google/oss-fuzz-vulns/blob/main/vulns/selinux/OSV-2021-421.yaml
oss-fuzz-vulns/OSV-2021-421.yaml at main · google/oss-fuzz-vulns · GitHubThird Party Advisory
-
https://github.com/SELinuxProject/selinux/commit/2d35fcc7e9e976a2346b1de20e54f8663e8a6cba
libsepol/cil: Destroy classperm list when resetting map perms · SELinuxProject/selinux@2d35fcc · GitHubPatch;Third Party Advisory
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