Executive brief
A security vulnerability exists in the SuperProbe utility, a tool used in older Linux distributions to identify video hardware. A local user can exploit this flaw to bypass security restrictions and gain full administrative (root) control over the system. This could lead to a complete compromise of the machine, including unauthorized access to all data and system settings.
Technical details
A classic stack-based buffer overflow exists within the TestChip function of the XFree86 SuperProbe utility. The vulnerability is triggered when the application processes an excessively long string provided via the '-nopr' command-line argument. Because SuperProbe was often installed with setuid root permissions to allow direct hardware access, an unprivileged local attacker can exploit this overflow to overwrite the instruction pointer and execute arbitrary code with elevated privileges. This results in a full local privilege escalation to root. Patch information is referenced in historical security archives, typically involving bounds checking on command-line inputs.
Affected products
- Slackware Slackware Linux 3.1
- XFree86 Project XFree86 SuperProbe
Timeline
- 1997-03-04: disclosed
- 1997-03-04: advisory