Server should meet the following PCI compliance requirements:
- Configure SSL/TLS servers to only use TLS 1.1 or TLS 1.2 if supported.
- Configure SSL/TLS servers to only support cipher suites that do not use block ciphers.
However, these protocols are not supported in Plesk by default.
PCI compliance requires that you enable the TLS 1.1 and TLS 1.2 protocols, but they are supported by Apache web server starting from 2.2.23 version.
Make sure that all system packages are up to date and the latest Plesk microupdate has installed
Follow instructions provided in the article #213933745 - CVE-2015-4000 LOGJAM TLS DH vulnerability