Horizon Alert
Summary of the vulnerability and why it matters
A vulnerability has been identified in a Plesk extension that could allow unauthorized code execution on servers. This issue stems from improper validation of identifiers, potentially enabling an attacker to gain elevated privileges and execute commands.
- Unvalidated identifiers allow unauthorized code execution.
- This could compromise server integrity and control.
- Confirm relevance and assess potential exposure.
Attack Path
How an attacker could exploit the issue
An attacker could exploit this by first gaining access as a non-owner subscription user on a Plesk server. This user could then leverage the "Site Import" extension's flawed validation of domain and session information to manipulate requests. By chaining this with a path traversal vulnerability, the attacker can redirect a privileged backend session to a directory they control, ultimately leading to the execution of arbitrary code with root privileges.
- Entry Condition: Access as a non-owner subscription user.
- Trigger Point: Manipulating domain and session identifiers.
- Resulting Risk: Arbitrary code execution as root.
Live Threat
Current exploitation, exposure, and threat context
The Plesk Site Import extension could allow an attacker to execute arbitrary code on the server as root under specific conditions. This could occur when a non-owner subscription user leverages a vulnerability in how domain and session identifiers are handled, enabling them to redirect a privileged backend session to a directory they control.
- Server code execution.
- Unauthenticated session redirection.
- Compromised server access.
Operational Fix
Recommended remediation, mitigation, and detection steps
The Plesk "Site Import" extension's path traversal vulnerability impacts systems where it's deployed, potentially requiring action from application owners, infrastructure teams, or security operations. The initial practical step is to identify all instances of the affected extension, assess their exposure and business criticality, and then locate the accountable owner to plan remediation.
- Identify affected Plesk instances and owners.
- Verify reachability and business impact.
- Plan remediation based on risk.
