SSL Certificate Chain Contains RSA Keys Less Than 2048 bits

Low Nessus Plugin ID 69551

Synopsis

The X.509 certificate chain used by this service contains certificates with RSA keys shorter than 2048 bits.

Description

At least one of the X.509 certificates sent by the remote host has a key that is shorter than 2048 bits. According to industry standards set by the Certification Authority/Browser (CA/B) Forum, certificates issued after January 1, 2014 must be at least 2048 bits.

Some browser SSL implementations may reject keys less than 2048 bits after January 1, 2014. Additionally, some SSL certificate vendors may revoke certificates less than 2048 bits before January 1, 2014.

Note that Nessus will not flag root certificates with RSA keys less than 2048 bits if they were issued prior to December 31, 2010, as the standard considers them exempt.

Solution

Replace the certificate in the chain with the RSA key less than 2048 bits in length with a longer key, and reissue any certificates signed by the old certificate.

See Also

https://www.cabforum.org/wp-content/uploads/Baseline_Requirements_V1.pdf

Plugin Details

Severity: Low

ID: 69551

File Name: ssl_weak_rsa_keys_under_2048.nasl

Version: 1.4

Type: remote

Family: General

Published: 2013/09/03

Updated: 2018/11/15

Dependencies: 57571

Risk Information

Risk Factor: Low

Vulnerability Information

Required KB Items: SSL/Chain/WeakRSA_Under_2048