Description
Acunetix detected that a certificate is signed using a weak signature algorithm.
The weak signature algorithm is known to be cryptographically weak and vulnerable to collision attacks.
Remediation
You'll need to generate a new certificate request, and get your CA to issue you a new certificate using SHA-2.
References
OWASP - Insecure Configuration Management
SHA1 Deprecation - What You Need to Know
Why Google is Hurrying the Web to Kill SHA-1
MD5 Considered Harmful Today - Creating a Rogue CA Certificate
OWASP Top 10-2017 A3-Sensitive Data Exposure
MS Security Advisory - Research Proves Feasibility of Collision Attacks Against MD5