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CVE Record

CVE-2021-36085: The CIL compiler in SELinux 3.2 has a use-after-free in __cil_verify_classperms (called from __verify_map_p...

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).

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

CVE-2021-36085 is a memory safety flaw in the SELinux CIL compiler, reported as a use-after-free in SELinux 3.2. The provided sources do not show active exploitation or a CVSS score, so urgency depends on whether vulnerable SELinux packages are present and exposed to untrusted policy inputs.

Executive priority

Treat as a dependency hygiene and platform assurance item, not a confirmed emergency. Prioritize patch validation where SELinux policy compilation occurs in automation, build systems, appliances, or security-sensitive Linux infrastructure.

Technical view

The flaw is in __cil_verify_classperms, reached through __verify_map_perm_classperms and hashtab_map in the CIL compiler. OSS-Fuzz reported it, and the source bundle cites a SELinuxProject commit plus Fedora and Debian advisories. Product and version impact beyond SELinux 3.2 is not fully enumerated here.

Likely exposure

Likely exposure is on systems or appliances that include affected SELinux userspace/CIL compiler packages. Highest practical concern is environments that compile or process CIL policy content from less-trusted sources. Confirm exact package status through distro or vendor advisories.

Exploitation context

The bundle does not provide evidence of public exploitation, KEV listing, exploit code, or real-world attacks. OSS-Fuzz involvement suggests discovery through fuzz testing rather than observed exploitation. Impact details are incomplete in the provided sources.

Researcher notes

Evidence is sparse: no CVSS, CWE, detailed affected CPEs, or exploit status is supplied. Focus analysis on package provenance, downstream backports, and whether policy compilation can be influenced by untrusted inputs.

Mitigation direction

  • Check vendor guidance for SELinux package updates addressing CVE-2021-36085.
  • Apply relevant Fedora, Debian, NetApp, or platform-specific security updates.
  • Confirm the cited SELinuxProject fix is included in deployed packages.
  • Avoid compiling untrusted CIL policy content until patched.

Validation and detection

  • Inventory systems and appliances that include SELinux userspace or CIL compiler packages.
  • Compare installed package versions against vendor advisories for this CVE.
  • Verify downstream packages include the cited SELinuxProject commit or equivalent fix.
  • Review build or automation workflows for untrusted CIL policy inputs.
Prepared
Confidence
medium
Sources
8

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

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CVE-2021-36085 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
0Timeline events
0ADP providers
7Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/an/an/aListed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.