The latest update for openssl, openssl-0.9.8e-12.el5_4.6, prevents Plesk from starting. This may not be evident until you try to restart Plesk, say after a Plesk update or server reboot. Plesk has a patch for this issue.

When trying to restart you may get a message about a ‘stale pidfile’ or you may see ‘Starting Plesk…. failed’. You will also see a number of SSL errors in the /var/log/sw-cp-server/error_log.

Until today, we’ve been downgrading openssl, httpd, and mod_ssl. Once performing the downgrade, you could restart Plesk successfully.

As of this afternoon, Plesk has issued a patch for the web engine, available in the Parallels Plesk Knowledgebase. Note Parallels has currently only released patches for CentOS 4/5 and RHEL 4. While it’s a good possibility that the CentOS 5 packages will work for RHEL 5, we would recommend waiting until an official RHEL 5 patch is released.

We’ve applied this to our clients’ CentOS 4/5 and RHEL 4 servers. After updating openssl, httpd, and mod_ssl we then applied the patch provided by Parallels. So far so good, we’ve not seen any issues.