CVE-2026-64667 | BDVDB-2026-404736 Detail
mcdopepam_usb
Description#
pam_usb provides hardware authentication for Linux using removable media. Prior to version 0.9.3, src/local.c (pusb_get_tty_from_display_server) allocates a 4096-byte cmdline buffer, reads up to 4096 bytes from /proc//cmdline, then replaces every NUL separator with a space. When read(2) returns exactly 4096 bytes for any process the function inspects, the buffer ends without a terminator and the subsequent strstr() calls scan past the allocation boundary. The function is invoked during normal PAM authentication when DISPLAY is set, so the read fires for every process at auth time. Consequences are bounded: strstr output is a Boolean substring match (limited info-disclosure surface) but a hostile heap layout can produce a SIGSEGV that terminates the host PAM process. This issue has been patched in version 0.9.3.
Impact#
Per CVSS v3.1: confidentiality impact low, integrity impact none, availability impact low. Attack vector: local.
Weaknesses#
- CWE-125 Out-of-bounds Read
References#
Exploit#
No public exploit known
History#
- Version 1Record published in the CVE List.