CVE-2025-40918

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.

CVSS v3 6.5 MEDIUM

6.5^/10

CVSS v3 : MEDIUM

V3 Legend

Vector :

Exploitability : 3.9 / Impact : 2.5

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://datatracker.ietf.org/doc/html/rfc2831
https://github.com/gbarr/perl-authen-sasl/pull/22
https://metacpan.org/dist/Authen-SASL/source/lib/Authen/SASL/Perl/DIGEST_MD5.pm#L263
https://metacpan.org/release/EHUELS/Authen-SASL-2.1900/changes
https://security.metacpan.org/patches/A/Authen-SASL/2.1800/CVE-2025-40918-r1.patch

Configurations

No configuration.

History

07 Aug 2025, 10:15

Type	Values Removed	Values Added
References		() https://metacpan.org/release/EHUELS/Authen-SASL-2.1900/changes -
Summary		(es) Authen::SASL::Perl::DIGEST_MD5, versiones 2.04 a 2.1800 para Perl, genera el cnonce de forma insegura. El cnonce (nonce del cliente) se genera a partir de un hash MD5 del PID, la fecha de la época y la función rand integrada. El PID se obtendrá de un pequeño conjunto de números, y la fecha de la época puede ser inferida si no se filtra del encabezado HTTP Date. La función rand integrada no es adecuada para uso criptográfico. Según la RFC 2831, el valor cnonce es una cadena opaca entre comillas proporcionada por el cliente y utilizada tanto por el cliente como por el servidor para evitar ataques de texto plano y proporcionar autenticación mutua. La seguridad de la implementación depende de una buena elección. Se recomienda que contenga al menos 64 bits de entropía.

16 Jul 2025, 21:15

Type	Values Removed	Values Added
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 6.5

16 Jul 2025, 15:15

Type	Values Removed	Values Added
References		() https://github.com/gbarr/perl-authen-sasl/pull/22 -
Summary	(en) 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."	(en) 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.

16 Jul 2025, 14:15

Type	Values Removed	Values Added
New CVE

Information

Published : 2025-07-16 14:15

Updated : 2025-08-07 10:15

NVD link : CVE-2025-40918

Mitre link : CVE-2025-40918

CVE.ORG link : CVE-2025-40918

JSON object : View

Products Affected

No product.

CWE

CWE-338

Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

CWE-340

Generation of Predictable Numbers or Identifiers

6.5 /10