CPANSA-Punk-TOTP-2026-78619: Punk-TOTP vulnerability

Publisher giterlizzi Document category csaf_security_advisory
Initial release date 2026-08-25T00:00:00 Engine CSAF Perl Toolkit 0.26
Current release date 2026-08-25T00:00:00 Build Date
Current version 1 Status final
CVSS v3.1 Base Score 9.8 Severity Critical
Original language Language en
Also referred to

Vulnerability Description

Punk::Plugin::TOTP versions before 0.05 for Perl accept another account's recovery code at the two-factor challenge because totp_use_recovery compares user identifiers numerically.

The helper searches the recovery model for the submitted code's digest alone, across every user's rows, so the ownership test that follows is the only thing binding a code to the account it was issued to. That test compares the row's user_id with the challenged user's id through Perl's integer coercion, and an identifier with no leading digits coerces to zero, so any two of them compare equal. User models keyed on a username, an email address or a UUID hit that case, and a numeric key compares as intended.

The challenge route feeds a submitted value to the helper once TOTP verification fails, so an attacker who knows a victim's password and holds a recovery code of their own passes the victim's second factor.

Vulnerabilities

CVE-2026-78619

Vulnerability Description

Punk::Plugin::TOTP versions before 0.05 for Perl accept another account's recovery code at the two-factor challenge because totp_use_recovery compares user identifiers numerically.

The helper searches the recovery model for the submitted code's digest alone, across every user's rows, so the ownership test that follows is the only thing binding a code to the account it was issued to. That test compares the row's user_id with the challenged user's id through Perl's integer coercion, and an identifier with no leading digits coerces to zero, so any two of them compare equal. User models keyed on a username, an email address or a UUID hit that case, and a numeric key compares as intended.

The challenge route feeds a submitted value to the helper once TOTP verification fails, so an attacker who knows a victim's password and holds a recovery code of their own passes the victim's second factor.

Weakness CWE-305 : Authentication Bypass by Primary Weakness

Product status

Known affected
Product Score
Punk-TOTP less than 0.05
CVSS Version CVSS Vector CVSS Base Score CVSS Base Severity
3.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H 9.8 Critical
Fixed

giterlizzi

Namespace: https://github.com/giterlizzi/

gdt@cpan.org

References

Revision history

Version Date of the revision Summary of the revision
1 Tue Aug 25 00:00:00 2026 First release

Sharing rules

TLP:WHITE
For the TLP version see: https://www.first.org/tlp/