CVE-2026-44709: CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') in mcdope pam_usb
pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.8.7, pamusb-pinentry reads the PINENTRY_FALLBACK_APP environment variable and executes it directly without any validation. Any process that can set environment variables before pamusb-pinentry is invoked can point PINENTRY_FALLBACK_APP at an arbitrary binary or script and have it executed with the privileges of the pam_usb tool chain. This vulnerability is fixed in 0.8.7.
AI Analysis
Technical Summary
The vulnerability in pam_usb (before version 0.8.7) involves improper neutralization of special elements used in an OS command (CWE-78). Specifically, pamusb-pinentry executes the PINENTRY_FALLBACK_APP environment variable directly without validation. An attacker able to control environment variables prior to pamusb-pinentry execution can cause arbitrary binaries or scripts to run with the privileges of the pam_usb tool chain. This can lead to full compromise of the affected system's authentication mechanism. The vulnerability is addressed by updating to pam_usb version 0.8.7 or later.
Potential Impact
Successful exploitation allows an attacker with the ability to set environment variables before pamusb-pinentry runs to execute arbitrary code with the privileges of the pam_usb tool chain. This can lead to complete compromise of authentication processes on the affected Linux system, impacting confidentiality, integrity, and availability.
Mitigation Recommendations
This vulnerability is fixed in pam_usb version 0.8.7. Users should upgrade to version 0.8.7 or later to remediate this issue. Patch status is not explicitly confirmed beyond the version fix note, so verify with the vendor advisory for the latest remediation guidance.
CVE-2026-44709: CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') in mcdope pam_usb
Description
pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.8.7, pamusb-pinentry reads the PINENTRY_FALLBACK_APP environment variable and executes it directly without any validation. Any process that can set environment variables before pamusb-pinentry is invoked can point PINENTRY_FALLBACK_APP at an arbitrary binary or script and have it executed with the privileges of the pam_usb tool chain. This vulnerability is fixed in 0.8.7.
CVSS v3.1
Score 7.8high
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in pam_usb (before version 0.8.7) involves improper neutralization of special elements used in an OS command (CWE-78). Specifically, pamusb-pinentry executes the PINENTRY_FALLBACK_APP environment variable directly without validation. An attacker able to control environment variables prior to pamusb-pinentry execution can cause arbitrary binaries or scripts to run with the privileges of the pam_usb tool chain. This can lead to full compromise of the affected system's authentication mechanism. The vulnerability is addressed by updating to pam_usb version 0.8.7 or later.
Potential Impact
Successful exploitation allows an attacker with the ability to set environment variables before pamusb-pinentry runs to execute arbitrary code with the privileges of the pam_usb tool chain. This can lead to complete compromise of authentication processes on the affected Linux system, impacting confidentiality, integrity, and availability.
Mitigation Recommendations
This vulnerability is fixed in pam_usb version 0.8.7. Users should upgrade to version 0.8.7 or later to remediate this issue. Patch status is not explicitly confirmed beyond the version fix note, so verify with the vendor advisory for the latest remediation guidance.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-05-07T17:07:09.318Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a175c27e29bf47b50eb6085
Added to database: 5/27/2026, 9:03:35 PM
Last enriched: 5/27/2026, 9:34:01 PM
Last updated: 5/29/2026, 9:03:08 AM
Views: 10
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