SSL Certificate Signed Using Weak Hashing Algorithm
Medium Nessus Plugin ID 35291
Synopsis
An SSL certificate in the certificate chain has been signed using a weak hash algorithm.
Description
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.
Solution
Contact the Certificate Authority to have the certificate reissued.