Bug#1109406: libauthen-sasl-perl: CVE-2025-40918

[Salvatore Bonaccorso]

Source: libauthen-sasl-perl
Version: 2.1700-1
Severity: important
Tags: security upstream
Forwarded: https://github.com/gbarr/perl-authen-sasl/pull/22
X-Debbugs-Cc: carnil at debian.org, Debian Security Team <team at security.debian.org>

Hi,

The following vulnerability was published for libauthen-sasl-perl.

CVE-2025-40918[0]:
| Authen::SASL::Perl::DIGEST_MD5 versions 2.04 through 2.1800 for Perl
| generates the cnonce insecurely.  The cnonce (client nonce) is
| generated from an MD5 hash of the PID, the epoch time and the built-
| in rand function. The PID will come from a small set of numbers, and
| the epoch time may be guessed, if it is not leaked from the HTTP
| Date header. The built-in rand function is unsuitable for
| cryptographic usage.  According to RFC 2831, The cnonce-value is an
| opaque quoted string value provided by the client and used by both
| client and server to avoid chosen plaintext attacks, and to provide
| mutual authentication. The security of the implementation  depends
| on a good choice. It is RECOMMENDED that it contain at least 64 bits
| of entropy.


If you fix the vulnerability please also make sure to include the
CVE (Common Vulnerabilities & Exposures) id in your changelog entry.

For further information see:

[0] https://security-tracker.debian.org/tracker/CVE-2025-40918
    https://www.cve.org/CVERecord?id=CVE-2025-40918
[1] https://github.com/gbarr/perl-authen-sasl/pull/22
[2] https://security.metacpan.org/patches/A/Authen-SASL/2.1800/CVE-2025-40918-r1.patch

Please adjust the affected versions in the BTS as needed.

Regards,
Salvatore