Description

The security flaw discovered in Plesk, a widely used web hosting and data center automation platform, allows attackers to gain total control of the affected servers. The vulnerability, which is tracked under CVE-2025-66430 and rated 9.1 on the CVSS scale, applies only to the Plesk for Linux version of the software and allows the perpetration of local privilege escalation (LPE). This means that users with limited access could escalate their privileges to obtain complete root access and thereby compromise the integrity of the server. The vulnerability lies in Plesk's access control for Password-Protected Directories. Due to inadequate validation of input data, attackers are able to inject arbitrary configuration data into the Apache server, with the result that commands can be executed with root-level privileges. This is very dangerous in a shared hosting environment because if one account is compromised, it would lead to a total takeover of the server affecting all websites and services hosted on it. Plesk has released emergency micro-updates to mitigate the threat and urged the administrators to act instantly. The affected versions are 18.0.73.5 and 18.0.74.2, while users on 18.0.70–18.0.72 must follow a special upgrade path. Older versions of Plesk Onyx are to be updated as well. Hence swift application of the patch is necessary to avoid exploitation and for the security of that server.