pam_usb: Symlink attacks on pad directory and pad files enable authentication bypass and root file corruption
Priority HIGH 70CWE-287Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- None · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-287.
Summary
pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.8.7, symlink attacks on pad directory and pad files enable authentication bypass and root file corruption. This vulnerability is fixed in 0.8.7.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00235 14th percentileScored 2026-11-07
Fix Fixed pam_usb (mcdope): 0.8.7
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA pam_usb (mcdope) Fixed in 0.8.7
Timeline
- 2026-10-02 Threatist record created from CVE-2026-44711
More mcdope vulnerabilities
- TI-2026-35505 pam_usb: PAM_RHOST check skipped when deny_remote=false allows XDMCP authentication bypass CVSS 3.1HIGH 8.1
- TI-2026-32596 pam_usb: PINENTRY_FALLBACK_APP environment variable allows arbitrary command execution CVSS 3.1HIGH 7.8
- TI-2026-32600 pam_usb: Command injection via $TMUX environment variable leads to RCE as root CVSS 3.1HIGH 8.8
- TI-2026-32599 pam_usb: Shell injection via device UUID and username in pamusb-conf and pamusb-agent CVSS 3.1HIGH 8.2
- TI-2026-34849 pam_usb: deny_remote feature incorrectly classifies IPv4-mapped IPv6 remote connections as local CVSS 3.1HIGH 7.4
- TI-2026-34852 pam_usb: OTP pad authentication bypass via missing system pad check and uninitialized RNG buffer CVSS 3.1HIGH 7.1
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences