Heap-based buffer overflow in QEMU - CVE-2016-9603
Published: June 6, 2017 / Updated: December 9, 2025
Vulnerability identifier: #VU6934
CSH Severity: High
CVSS v4.0: CVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:U/U:Amber
CVE-ID: CVE-2016-9603
CWE-ID: CWE-122
Exploitation vector: Adjecent network
Exploit availability:
No public exploit available
Vendor: QEMU
Affected software:
QEMU
QEMU
Detailed vulnerability description
The vulnerability allows a local user to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error in Cirrus CLGD 54xx VGA emulator's VNC display driver when a VNC client attempted to update its display after a VGA operation is performed by a guest. A local user inside a guest VM can trigger a hea-based buffer overflow and execute arbitrary code with privileges of the QEMU process.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
How to mitigate CVE-2016-9603
Install update from vendor's website.