CVE-2023-6816
CWE-787Published: January 18, 2024· Updated: Jun 17, 2026
Official Description
A flaw was found in X.Org server. Both DeviceFocusEvent and the XIQueryPointer reply contain a bit for each logical button currently down. Buttons can be arbitrarily mapped to any value up to 255, but the X.Org Server was only allocating space for the device's particular number of buttons, leading to a heap overflow if a bigger value was used.
Risk Analysis
A heap overflow vulnerability exists in the X.Org server due to improper memory allocation when handling logical button mappings. This critical flaw is remotely exploitable with low complexity, posing a significant risk to system integrity and availability.
There is no known public exploit for this vulnerability, and it is not listed in the CISA KEV catalog.
Users should update the X.Org server and Xwayland packages to the latest versions provided by their distribution maintainers.
Technical Analysis
CVE-2023-6816 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.
From a weakness classification perspective (CWE-787): Out-of-bounds write vulnerabilities can lead to data corruption, crashes, or arbitrary code execution.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (39)
Quick Facts
Related CVEs (CWE-787)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2023-6816 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts