# CVE-2025-40918: Authen::SASL::Perl::DIGEST_MD5 versions 2.04 through 2.1800 for Perl generates the cnonce insecurely > Insecure cnonce generation in Perl SASL DIGEST-MD5 allows attackers to bypass mutual authentication and chosen plaintext protections. - **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 16 Jul 2025 - **Updated:** 4 Nov 2025 - **Also known as:** ALPINE-CVE-2025-40918, AZL-65541, BELL-CVE-2025-40918, DEBIAN-CVE-2025-40918, GHSA-496q-8ph2-c4fj, MGASA-2025-0285, OESA-2026-2422, OESA-2026-2423, OESA-2026-2530, OESA-2026-2531, SUSE-SU-2025:03087-1, SUSE-SU-2025:03088-1, SUSE-SU-2026:21145-1, UBUNTU-CVE-2025-40918, openSUSE-SU-2025:15385-1, openSUSE-SU-2026:20480-1 ## 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 (Generation of Predictable Numbers or Identifiers), CWE-338 (Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)) ## Which versions are affected by CVE-2025-40918? | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `perl-Authen-SASL` | SUSE:Enterprise Storage 7.1 | All versions | 2.16-150000.1.6.1 | | `perl-Crypt-URandom` | SUSE:Enterprise Storage 7.1 | All versions | 0.540.0-150000.1.3.1 | | `perl-Authen-SASL` | SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSS | All versions | 2.16-150000.1.6.1 | | `perl-Crypt-URandom` | SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSS | All versions | 0.540.0-150000.1.3.1 | | `perl-Authen-SASL` | SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | All versions | 2.16-150000.1.6.1 | | `perl-Crypt-URandom` | SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | All versions | 0.540.0-150000.1.3.1 | | `perl-Authen-SASL` | SUSE:Linux Enterprise High Performance Computing 15 SP4-LTSS | All versions | 2.16-150000.1.6.1 | | `perl-Crypt-URandom` | SUSE:Linux Enterprise High Performance Computing 15 SP4-LTSS | All versions | 0.540.0-150000.1.3.1 | | `perl-Authen-SASL` | SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOS | All versions | 2.16-150000.1.6.1 | | `perl-Crypt-URandom` | SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOS | All versions | 0.540.0-150000.1.3.1 | | `perl-Authen-SASL` | SUSE:Linux Enterprise High Performance Computing 15 SP5-LTSS | All versions | 2.16-150000.1.6.1 | | `perl-Crypt-URandom` | SUSE:Linux Enterprise High Performance Computing 15 SP5-LTSS | All versions | 0.540.0-150000.1.3.1 | | `perl-Authen-SASL` | SUSE:Linux Enterprise Module for Development Tools 15 SP6 | All versions | 2.16-150000.1.6.1 | | `perl-Crypt-URandom` | SUSE:Linux Enterprise Module for Development Tools 15 SP6 | All versions | 0.540.0-150000.1.3.1 | | `perl-Authen-SASL` | SUSE:Linux Enterprise Module for Development Tools 15 SP7 | All versions | 2.16-150000.1.6.1 | | `perl-Crypt-URandom` | SUSE:Linux Enterprise Module for Development Tools 15 SP7 | All versions | 0.540.0-150000.1.3.1 | | `perl-Authen-SASL` | SUSE:Linux Enterprise Server 12 SP5-LTSS | All versions | 2.16-5.3.1 | | `perl-Crypt-URandom` | SUSE:Linux Enterprise Server 12 SP5-LTSS | All versions | 0.540.0-1.3.1 | | `perl-Authen-SASL` | SUSE:Linux Enterprise Server 15 SP3-LTSS | All versions | 2.16-150000.1.6.1 | | `perl-Crypt-URandom` | SUSE:Linux Enterprise Server 15 SP3-LTSS | All versions | 0.540.0-150000.1.3.1 | | `perl-Authen-SASL` | SUSE:Linux Enterprise Server 15 SP4-LTSS | All versions | 2.16-150000.1.6.1 | | `perl-Crypt-URandom` | SUSE:Linux Enterprise Server 15 SP4-LTSS | All versions | 0.540.0-150000.1.3.1 | | `perl-Authen-SASL` | SUSE:Linux Enterprise Server 15 SP5-LTSS | All versions | 2.16-150000.1.6.1 | | `perl-Crypt-URandom` | SUSE:Linux Enterprise Server 15 SP5-LTSS | All versions | 0.540.0-150000.1.3.1 | | `perl-Authen-SASL` | SUSE:Linux Enterprise Server 16.0 | All versions | 2.170.0-160000.3.1 | | `perl-Crypt-URandom` | SUSE:Linux Enterprise Server 16.0 | All versions | 0.550.0-160000.1.1 | | `perl-Authen-SASL` | SUSE:Linux Enterprise Server LTSS Extended Security 12 SP5 | All versions | 2.16-5.3.1 | | `perl-Crypt-URandom` | SUSE:Linux Enterprise Server LTSS Extended Security 12 SP5 | All versions | 0.540.0-1.3.1 | | `perl-Authen-SASL` | SUSE:Linux Enterprise Server for SAP Applications 15 SP3 | All versions | 2.16-150000.1.6.1 | | `perl-Crypt-URandom` | SUSE:Linux Enterprise Server for SAP Applications 15 SP3 | All versions | 0.540.0-150000.1.3.1 | | `perl-Authen-SASL` | SUSE:Linux Enterprise Server for SAP Applications 15 SP4 | All versions | 2.16-150000.1.6.1 | | `perl-Crypt-URandom` | SUSE:Linux Enterprise Server for SAP Applications 15 SP4 | All versions | 0.540.0-150000.1.3.1 | | `perl-Authen-SASL` | SUSE:Linux Enterprise Server for SAP Applications 15 SP5 | All versions | 2.16-150000.1.6.1 | | `perl-Crypt-URandom` | SUSE:Linux Enterprise Server for SAP Applications 15 SP5 | All versions | 0.540.0-150000.1.3.1 | | `perl-Authen-SASL` | SUSE:Linux Enterprise Server for SAP applications 16.0 | All versions | 2.170.0-160000.3.1 | | `perl-Crypt-URandom` | SUSE:Linux Enterprise Server for SAP applications 16.0 | All versions | 0.550.0-160000.1.1 | | `perl-Authen-SASL` | openSUSE:Leap 15.6 | All versions | 2.16-150000.1.6.1 | | `perl-Crypt-URandom` | openSUSE:Leap 15.6 | All versions | 0.540.0-150000.1.3.1 | | `perl-Authen-SASL` | openSUSE:Leap 16.0 | All versions | 2.170.0-160000.3.1 | | `perl-Crypt-URandom` | openSUSE:Leap 16.0 | All versions | 0.550.0-160000.1.1 | ## 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. ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2025-40918 and fix it if it is affected. What it is: 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. Exploitation: There is no known exploitation of CVE-2025-40918 in the wild and no public exploit code. Affected product: EHUELS Authen::SASL::Perl::DIGEST_MD5. No package-level version data is available, so check the vendor advisory linked from the reference page. Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2025-40918/ (Markdown: https://insights.sbomify.com/CVE-2025-40918/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2025-40918 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-40918 - OSV: https://osv.dev/vulnerability/CVE-2025-40918 --- From sbomify Insights: https://insights.sbomify.com/CVE-2025-40918/ Summaries are generated and may contain mistakes; the official description above is the record.