Advisory Details

December 9th, 2020

X.Org Server XkbSetNames Out-Of-Bounds Access Privilege Escalation Vulnerability

ZDI-20-1416
ZDI-CAN-11428

CVE ID CVE-2020-14345
CVSS SCORE 7.8, (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
AFFECTED VENDORS X.Org
AFFECTED PRODUCTS Server
VULNERABILITY DETAILS

This vulnerability allows local attackers to escalate privileges on affected installations of X.Org Server. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability.

The specific flaw exists within the handling of XkbSetNames requests. The issue results from the lack of proper validation of user-supplied data, which can result in a memory access past the end of an allocated data structure. An attacker can leverage this vulnerability to escalate privileges and execute code in the context of root.

ADDITIONAL DETAILS X.Org has issued an update to correct this vulnerability. More details can be found at:
https://lists.x.org/archives/xorg-announce/2020-August/003058.html
DISCLOSURE TIMELINE
  • 2020-07-24 - Vulnerability reported to vendor
  • 2020-12-09 - Coordinated public release of advisory
CREDIT Jan-Niklas Sohn
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