EUVD-2026-32647CVSS VectorNVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Lifecycle Timeline
2DescriptionNVD
pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.9.1, src/evdev.c silently ignores EACCES errors when opening /dev/input/event* nodes, causing pusb_has_virtual_input_device() to return 0 (no virtual devices found) even when every open() call failed due to insufficient permissions. The caller in src/local.c cannot distinguish a clean absence of virtual devices from a permission-denied scan, and acts on the false negative by continuing authentication without denying. This vulnerability is fixed in 0.9.1.
AnalysisAI
Authentication bypass in pam_usb prior to 0.9.1 allows a local low-privileged user to circumvent hardware token requirements by exploiting silent EACCES error suppression in the virtual input device scanner. When the PAM module's evdev.c component fails to open /dev/input/event* nodes due to permission errors, it returns a false negative indicating no virtual devices are present, and the caller in local.c proceeds with authentication as if the hardware check passed cleanly. …
Sign in for full analysis, threat intelligence, and remediation guidance.
Share
External POC / Exploit Code
Leaving vuln.today