{"id":"CVE-2026-47272","aliases":["EUVD-2026-32653","GHSA-vx6f-rrqr-j87c"],"status":"published","title":"pam_usb: OTP pad authentication bypass via missing system pad check and uninitialized RNG buffer","description":"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.","severity":{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00119,"percentile":0.01758,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-287","CWE-908"],"published":"2026-05-27T20:06:15Z","modified":"2026-10-28T11:11:17Z","products":[{"vendor":"mcdope","product":"pam_usb"}],"references":[{"url":"https://github.com/mcdope/pam_usb/security/advisories/GHSA-vx6f-rrqr-j87c","tags":["x_refsource_CONFIRM","advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/47xxx/CVE-2026-47272.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-47272","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-47272","title":"pam_usb: OTP pad authentication bypass via missing system pad check and uninitialized RNG buffer","description":"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.","status":"published","published":"2026-05-27T20:06:15.388Z","modified":"2026-05-28T12:53:00.432Z","cvss":[{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N","level":"high","assessor":"cna"}],"cwes":["CWE-287","CWE-908"],"updated_at":"2026-11-02T13:36:40.478484Z"}],"euvd":[{"id":"EUVD-2026-32653","description":"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.","status":"published","published":"2026-05-27T20:06:15Z","modified":"2026-05-28T12:53:00Z","cvss":[{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N","level":"high"}],"updated_at":"2026-11-02T18:21:03.0662Z"}],"nvd":[{"id":"CVE-2026-47272","description":"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.","status":"published","published":"2026-05-27T20:16:39.747Z","modified":"2026-10-26T11:10:00.157Z","cvss":[{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N","level":"high","assessor":"secondary"}],"cwes":["CWE-287","CWE-908"],"updated_at":"2026-11-02T14:12:20.885865Z"}],"osv":[{"id":"CVE-2026-47272","title":"pam_usb: OTP pad authentication bypass via missing system pad check and uninitialized RNG buffer","description":"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.","status":"published","published":"2026-05-27T20:06:15.388Z","modified":"2026-10-28T11:11:17.042857821Z","cvss":[{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N","level":"high"}],"cwes":["CWE-287","CWE-908"],"updated_at":"2026-11-02T15:45:06.231145Z"}]}}