CVSS VectorNVD
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H
Lifecycle Timeline
3DescriptionNVD
pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.9.1, src/log.c contains a process-wide static pointer that is written on every PAM invocation with the address of a stack-local variable. This violates the PAM re-entrancy requirement and creates a data race when the PAM stack is invoked concurrently from multiple threads. This vulnerability is fixed in 0.9.1.
AnalysisAI
Concurrent PAM invocations in pam_usb prior to 0.9.1 expose a process-wide static pointer race condition in src/log.c, where each PAM call overwrites a shared static pointer with the address of a stack-local variable. When multiple threads invoke the PAM stack simultaneously - a normal condition in multi-threaded Linux services such as SSH daemons or display managers - one thread's logging pointer can reference another thread's already-deallocated stack frame, causing availability loss (crash/hang) or limited integrity corruption. …
Sign in for full analysis, threat intelligence, and remediation guidance.
Share
External POC / Exploit Code
Leaving vuln.today
EUVD-2026-32648