CVE-2025-40918 Authen::SASL::Perl::DIGEST_MD5 versions 2.04 through 2.1800 for Perl generates the cnonce insecurely

Medium 6.5 Published Updated

Insecure cnonce generation in Perl SASL DIGEST-MD5 allows attackers to bypass mutual authentication and chosen plaintext protections.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
Not needed
Fix
Available

What is CVE-2025-40918?

CVE-2025-40918 is a medium-severity vulnerability in EHUELS Authen::SASL::Perl::DIGEST_MD5, published on 16 Jul 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

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.

Weakness: CWE-340, CWE-338

Which versions are affected by CVE-2025-40918?

Linux distribution packages (40)
perl-Authen-SASL SUSE:Enterprise Storage 7.1All versions2.16-150000.1.6.1
perl-Crypt-URandom SUSE:Enterprise Storage 7.1All versions0.540.0-150000.1.3.1
perl-Authen-SASL SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSSAll versions2.16-150000.1.6.1
perl-Crypt-URandom SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSSAll versions0.540.0-150000.1.3.1
perl-Authen-SASL SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOSAll versions2.16-150000.1.6.1
perl-Crypt-URandom SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOSAll versions0.540.0-150000.1.3.1
perl-Authen-SASL SUSE:Linux Enterprise High Performance Computing 15 SP4-LTSSAll versions2.16-150000.1.6.1
perl-Crypt-URandom SUSE:Linux Enterprise High Performance Computing 15 SP4-LTSSAll versions0.540.0-150000.1.3.1
perl-Authen-SASL SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOSAll versions2.16-150000.1.6.1
perl-Crypt-URandom SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOSAll versions0.540.0-150000.1.3.1
perl-Authen-SASL SUSE:Linux Enterprise High Performance Computing 15 SP5-LTSSAll versions2.16-150000.1.6.1
perl-Crypt-URandom SUSE:Linux Enterprise High Performance Computing 15 SP5-LTSSAll versions0.540.0-150000.1.3.1
perl-Authen-SASL SUSE:Linux Enterprise Module for Development Tools 15 SP6All versions2.16-150000.1.6.1
perl-Crypt-URandom SUSE:Linux Enterprise Module for Development Tools 15 SP6All versions0.540.0-150000.1.3.1
perl-Authen-SASL SUSE:Linux Enterprise Module for Development Tools 15 SP7All versions2.16-150000.1.6.1
perl-Crypt-URandom SUSE:Linux Enterprise Module for Development Tools 15 SP7All versions0.540.0-150000.1.3.1
perl-Authen-SASL SUSE:Linux Enterprise Server 12 SP5-LTSSAll versions2.16-5.3.1
perl-Crypt-URandom SUSE:Linux Enterprise Server 12 SP5-LTSSAll versions0.540.0-1.3.1
perl-Authen-SASL SUSE:Linux Enterprise Server 15 SP3-LTSSAll versions2.16-150000.1.6.1
perl-Crypt-URandom SUSE:Linux Enterprise Server 15 SP3-LTSSAll versions0.540.0-150000.1.3.1
perl-Authen-SASL SUSE:Linux Enterprise Server 15 SP4-LTSSAll versions2.16-150000.1.6.1
perl-Crypt-URandom SUSE:Linux Enterprise Server 15 SP4-LTSSAll versions0.540.0-150000.1.3.1
perl-Authen-SASL SUSE:Linux Enterprise Server 15 SP5-LTSSAll versions2.16-150000.1.6.1
perl-Crypt-URandom SUSE:Linux Enterprise Server 15 SP5-LTSSAll versions0.540.0-150000.1.3.1
perl-Authen-SASL SUSE:Linux Enterprise Server 16.0All versions2.170.0-160000.3.1
perl-Crypt-URandom SUSE:Linux Enterprise Server 16.0All versions0.550.0-160000.1.1
perl-Authen-SASL SUSE:Linux Enterprise Server LTSS Extended Security 12 SP5All versions2.16-5.3.1
perl-Crypt-URandom SUSE:Linux Enterprise Server LTSS Extended Security 12 SP5All versions0.540.0-1.3.1
perl-Authen-SASL SUSE:Linux Enterprise Server for SAP Applications 15 SP3All versions2.16-150000.1.6.1
perl-Crypt-URandom SUSE:Linux Enterprise Server for SAP Applications 15 SP3All versions0.540.0-150000.1.3.1
perl-Authen-SASL SUSE:Linux Enterprise Server for SAP Applications 15 SP4All versions2.16-150000.1.6.1
perl-Crypt-URandom SUSE:Linux Enterprise Server for SAP Applications 15 SP4All versions0.540.0-150000.1.3.1
perl-Authen-SASL SUSE:Linux Enterprise Server for SAP Applications 15 SP5All versions2.16-150000.1.6.1
perl-Crypt-URandom SUSE:Linux Enterprise Server for SAP Applications 15 SP5All versions0.540.0-150000.1.3.1
perl-Authen-SASL SUSE:Linux Enterprise Server for SAP applications 16.0All versions2.170.0-160000.3.1
perl-Crypt-URandom SUSE:Linux Enterprise Server for SAP applications 16.0All versions0.550.0-160000.1.1
perl-Authen-SASL openSUSE:Leap 15.6All versions2.16-150000.1.6.1
perl-Crypt-URandom openSUSE:Leap 15.6All versions0.540.0-150000.1.3.1
perl-Authen-SASL openSUSE:Leap 16.0All versions2.170.0-160000.3.1
perl-Crypt-URandom openSUSE:Leap 16.0All versions0.550.0-160000.1.1

How do I fix CVE-2025-40918?

Apply the vendor's patch.

Is CVE-2025-40918 being exploited?

There is no known exploitation of CVE-2025-40918 in the wild and no public exploit code.

Sources

Also known as ALPINE-CVE-2025-40918, AZL-65541, BELL-CVE-2025-40918, DEBIAN-CVE-2025-40918, GHSA-496q-8ph2-c4fj, MGASA-2025-0285 and 10 more.

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