CVE-2026-64666 | BDVDB-2026-404735 Detail
mcdopepam_usb
Description#
pam_usb provides hardware authentication for Linux using removable media. Prior to version 0.9.3, src/local.c reads XRDP_SESSION with plain getenv(3) at the head of pusb_local_login while every other env consumer in the same function uses secure_getenv(3). When pam_usb.so loads into a setuid PAM host, the calling user controls the environment passed in. Clearing XRDP_SESSION before invoking the host bypasses the explicit XRDP-deny rule. Other remote-detection signals (rmsvc, evdev, loginctl, utmp) may still catch the session, but the env-based detection alone is defeated. This issue has been patched in version 0.9.3.
Impact#
Per CVSS v3.1: confidentiality impact high, integrity impact high, availability impact none. Attack vector: local.
Weaknesses#
- CWE-807 Reliance on Untrusted Inputs in a Security Decision
References#
Exploit#
No public exploit known
History#
- Version 1Record published in the CVE List.