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.