CVE-2026-47272

high

Description

pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.9.0, the pusb_pad_compare() function in src/pad.c only verified that the user-side pad (~/.pamusb/device.pad) could be read, but did not enforce that the system-side pad (the pad file on the USB device) was also present and readable. If the user-side pad was deleted or unreadable, the function returned a failure that was treated as non-fatal in certain code paths, allowing authentication to succeed without the USB device being verified. A local user can delete their own ~/.pamusb/device.pad to remove the USB device requirement and authenticate without the physical device. This vulnerability is fixed in 0.9.0.

References

https://github.com/mcdope/pam_usb/security/advisories/GHSA-vx6f-rrqr-j87c

Details

Source: Mitre, NVD

Published: 2026-05-27

Updated: 2026-05-27

Risk Information

CVSS v2

Base Score: 6.2

Vector: CVSS2#AV:L/AC:L/Au:S/C:C/I:C/A:N

Severity: Medium

CVSS v3

Base Score: 7.1

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

Severity: High