CVE-2021-36086

Severity: low (CVSS 3.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2021-07-01 · updated 2026-10-14
Weakness: CWE-416

Description

The CIL compiler in SELinux 3.2 has a use-after-free in cil_reset_classpermission (called from cil_reset_classperms_set and cil_reset_classperms_list).

Affected products

Debian Linux: 11.0
Fedoraproject Fedora: 35
Active IQ Unified Manager for VMware vSphere, Linux, and Microsoft Windows: all versions
NetApp Bootstrap Os: all versions
NetApp H610C Firmware: all versions
NetApp H610S Firmware: all versions
NetApp H615C Firmware: all versions
SELinux Project Selinux: before 3.3 — fixed in 3.3

How to fix

Upgrade to a fixed version: SELinux Project Selinux 3.3. Check the vendor advisory for mitigations.

References

https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=32177
https://github.com/SELinuxProject/selinux/commit/c49a8ea09501ad66e799ea41b8154b6770fec2c8
https://github.com/google/oss-fuzz-vulns/blob/main/vulns/selinux/OSV-2021-536.yaml
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/U7ZYR3PIJ75N6U2IONJWCKZ5L2NKJTGR/
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=32177
https://github.com/SELinuxProject/selinux/commit/c49a8ea09501ad66e799ea41b8154b6770fec2c8
https://github.com/google/oss-fuzz-vulns/blob/main/vulns/selinux/OSV-2021-536.yaml
https://lists.debian.org/debian-lts-announce/2024/10/msg00021.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/U7ZYR3PIJ75N6U2IONJWCKZ5L2NKJTGR/
https://security.netapp.com/advisory/ntap-20250207-0004/
https://cert-portal.siemens.com/productcert/html/ssa-202008.html
https://cert-portal.siemens.com/productcert/html/ssa-398330.html

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