A local privilege escalation vulnerability in Sonarr 4.0.15.2940 allows attackers with local access to manipulate service permissions and potentially gain elevated system control.

This vulnerability is caused by incorrect default permissions in the Sonarr.Console.exe service. Exploitation requires an attacker to already have local system access to interact with the service environment.

The exploitation of this flaw could allow a local user to escalate their privileges, potentially resulting in full system compromise. With a CVSS score of 7.8, the vulnerability poses a significant risk to the confidentiality and integrity of the host system, particularly in environments where multiple users or processes share the same host.

Immediate Action: Since a specific patch is not yet available, ensure the Sonarr service is configured to run under a low privilege account rather than a high privilege or administrative account.

Proactive Monitoring: Monitor system logs for unauthorized attempts to modify service configurations or unexpected execution of the Sonarr console binary.

Compensating Controls: Implement strict file system permissions on the Sonarr installation directory to prevent non-administrative users from modifying or replacing the executable files.

Public Exploit Available: No — there is no confirmed public exploit or weaponized module available.

Security teams should prioritize restricting access to the Sonarr service configuration and ensuring the application runs with the principle of least privilege. Given that a fix is pending for the next major release, users should monitor official vendor communications for the availability of version 5 and apply the update as soon as it is released.