Description
pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.9.0, multiple pam_usb helper tools resolved external binaries through the PATH environment variable rather than using absolute paths. An attacker who can influence the process environment during PAM authentication or tool execution could substitute malicious binaries. The affected tools are pamusb-check (src/tmux.c), pamusb-conf (tools/pamusb-conf), and pamusb-keyring-unlock-gnome (tools/pamusb-keyring-unlock-gnome). This vulnerability is fixed in 0.9.0.
CVSS breakdown
CVSS 3.1
Attack Vector
Local
Attack Complexity
High
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None
Affected products
- mcdope / pam_usb< 0.9.0 – < 0.9.0
References
- VENDOR_ADVISORYhttps://github.com/mcdope/pam_usb/security/advisories/GHSA-pp29-w28g-r9h9
- PATCHhttps://github.com/mcdope/pam_usb/commit/1ee8745920388df48d001a8e61ba629071557937
- PATCHhttps://github.com/mcdope/pam_usb/commit/52a1fd6413b7ffcc1a5b58ce432be42e7bf0dbd0
- PATCHhttps://github.com/mcdope/pam_usb/commit/993e73d8bebb1d8e62677388de3402b6ec36b600