The MD5 Message-Digest Algorithm is not collision resistant, which makes it easier for context-dependent attackers to conduct spoofing attacks, as demonstrated by attacks on the use of MD5 in the signature algorithm of an X.509 certificate.

The remote Redhat Enterprise Linux 5 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2010:0838 advisory.

  - MD5: MD5 Message-Digest Algorithm is not collision resistant (CVE-2004-2761)

  - Certificate System: unauthenticated user can request SCEP one-time PIN decryption (CVE-2010-3868)

  - Certificate System: SCEP one-time PIN reuse (CVE-2010-3869)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote service uses an SSL certificate that has been signed using a cryptographically weak hashing algorithm - MD5. This algorithm is known to be vulnerable to collision attacks. In theory, a determined attacker may be able to leverage this weakness to generate another certificate with the same digital signature, which could allow them to masquerade as the affected service.

The MD5 algorithm is known not to be collision resistant. This update blacklists the proof of concept rogue certificate authority as discussed in http://www.win.tue.nl/hashclash/rogue-ca/.

Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

This updates adds protection against rogue CA that was generated as a proof-of- concept of the MD5 collision attacks against X509 signatures: http://www.win.tue.nl/hashclash/rogue-ca/ , related to CVE-2004-2761.

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

The remote service uses an SSL certificate that has been signed using a cryptographically weak hashing algorithm - MD2.  These algorithms are known to be vulnerable to collision attacks.  In theory, a determined attacker may be able to leverage this weakness to generate another certificate with the same digital signature, which could allow him to masquerade as the affected service.

The remote service uses an SSL certificate that has been signed using a cryptographically weak hashing algorithm - MD4.  These algorithms are known to be vulnerable to collision attacks.  In theory, a determined attacker may be able to leverage this weakness to generate another certificate with the same digital signature, which could allow him to masquerade as the affected service.

The remote service uses an SSL certificate that has been signed using a cryptographically weak hashing algorithm - MD5.  These algorithms are known to be vulnerable to collision attacks.  In theory, a determined attacker may be able to leverage this weakness to generate another certificate with the same digital signature, which could allow him to masquerade as the affected service.

The remote service uses an SSL certificate chain that has been signed using a cryptographically weak hashing algorithm (e.g. MD2, MD4, MD5, or SHA1). These signature algorithms are known to be vulnerable to collision attacks. An attacker can exploit this to generate another certificate with the same digital signature, allowing an attacker to masquerade as the affected service.

Note that this plugin reports all SSL certificate chains signed with SHA-1 that expire after January 1, 2017 as vulnerable. This is in accordance with Google's gradual sunsetting of the SHA-1 cryptographic hash algorithm.

Note that certificates in the chain that are contained in the Nessus CA database (known_CA.inc) have been ignored.

ID	Name	Product	Family	Severity
193666	RHEL 5 : pki (RHSA-2010:0838)	Nessus	Red Hat Local Security Checks	critical
7201	TLS Certificate Signed Using Weak Hashing Algorithm - MD5	Nessus Network Monitor	Generic	medium
37463	Ubuntu 6.06 LTS / 7.10 / 8.04 LTS / 8.10 : nss, firefox vulnerability (USN-740-1)	Nessus	Ubuntu Local Security Checks	medium
35595	Fedora 9 : nss-3.12.2.0-2.fc9 (2009-1276)	Nessus	Fedora Local Security Checks	medium
4805	SSL Certificate Signed Using Weak Hashing Algorithm	Nessus Network Monitor	Generic	medium
4804	SSL Certificate Signed Using Weak Hashing Algorithm	Nessus Network Monitor	Generic	medium
4803	SSL Certificate Signed Using Weak Hashing Algorithm	Nessus Network Monitor	Generic	medium
35291	SSL Certificate Signed Using Weak Hashing Algorithm	Nessus	General	high

Detections

Analytics

CVE-2004-2761

critical

Tenable Plugins

critical

medium

medium

medium

medium

medium

medium

high