CVE-2026-27626: OliveTin

Overview

A critical security vulnerability has been identified in OliveTin, a tool that provides a web interface for running predefined shell commands. This flaw allows attackers to execute arbitrary commands on the host system running OliveTin, potentially leading to full system compromise.

Vulnerability Details

The vulnerability consists of two primary attack vectors that can be combined for maximum impact.

Vector 1: Argument Type Bypass OliveTin’s safety check for shell commands (checkShellArgumentSafety) fails to block the password argument type. An authenticated user can inject malicious shell code through this argument, bypassing intended security controls.

Vector 2: Webhook Data Processing Bypass When OliveTin processes incoming webhook data, extracted JSON values are not subjected to the same type safety checks before being passed to the shell. This allows unauthenticated remote code execution if the instance is configured to accept webhooks-a common setup.

Impact

The impact of this vulnerability is severe (CVSS: 9.9):

• Authenticated Attackers: Any user with an account (registration is enabled by default) can execute arbitrary operating system commands with the privileges of the OliveTin process.
• Unauthenticated Attackers: If the OliveTin instance receives webhooks from external sources, unauthenticated attackers can achieve the same level of access without needing credentials.
• System Compromise: Successful exploitation can lead to complete control of the host system, data theft, deployment of malware, or use as a foothold for further network attacks.

Affected Versions

All versions of OliveTin up to and including 3000.10.0 are vulnerable. At the time of publication, a patched version is not available.

Remediation and Mitigation

Given no patch is currently available, immediate mitigation is critical.

1. Restrict Network Access: Immediately ensure the OliveTin web interface and webhook endpoints are not exposed to the internet or untrusted networks. Restrict access to only trusted, necessary users via network controls.
2. Review Authentication: If possible, change the authType from none and disable user registration to reduce the attack surface. Note this only mitigates Vector 1.
3. Disable or Isolate: Consider temporarily disabling OliveTin instances, especially those processing external webhooks, until a fix is released.
4. Monitor for Updates: Closely monitor the official OliveTin project channels for the release of a security patch. Apply it immediately upon availability.
5. Review Systems: Assume compromise is possible. Review affected systems for any signs of unauthorized access or anomalous activity.

Conclusion

This is a critical vulnerability that enables remote code execution. Organizations using OliveTin must implement the suggested mitigations immediately to protect their systems. The risk is particularly high for instances accessible from the internet or those configured to accept webhooks.