{"id":"CVE-2026-47272","summary":"pam_usb: OTP pad authentication bypass via missing system pad check and uninitialized RNG buffer","details":"pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.9.0, the pusb_pad_compare() function in src/pad.c only verified that the user-side pad (~/.pamusb/device.pad) could be read, but did not enforce that the system-side pad (the pad file on the USB device) was also present and readable. If the user-side pad was deleted or unreadable, the function returned a failure that was treated as non-fatal in certain code paths, allowing authentication to succeed without the USB device being verified. A local user can delete their own ~/.pamusb/device.pad to remove the USB device requirement and authenticate without the physical device. This vulnerability is fixed in 0.9.0.","aliases":["GHSA-vx6f-rrqr-j87c"],"modified":"2026-07-08T08:13:38.045260816Z","published":"2026-05-27T20:06:15.388Z","database_specific":{"cwe_ids":["CWE-287","CWE-908"],"cna_assigner":"GitHub_M","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/47xxx/CVE-2026-47272.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/47xxx/CVE-2026-47272.json"},{"type":"ADVISORY","url":"https://github.com/mcdope/pam_usb/security/advisories/GHSA-vx6f-rrqr-j87c"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-47272"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/mcdope/pam_usb","events":[{"introduced":"0"},{"fixed":"c1eba240c30dc377619492affca6f0c130e4fa9e"}],"database_specific":{"source":"AFFECTED_FIELD","extracted_events":[{"introduced":"0"},{"fixed":"0.9.0"}]}}],"versions":["0.8.7","0.8.4","0.8.3","v0.8.0","0.7.3","0.7.2","0.7.1","v0.7.0","0.5.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-47272.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N"}]}