CVE-2026-27626
📋 TL;DR
CVE-2026-27626 allows authenticated users to execute arbitrary OS commands on OliveTin hosts by injecting shell metacharacters through password-type arguments. Unauthenticated attackers can also achieve remote code execution via webhook-triggered actions that bypass type safety checks. All OliveTin instances up to version 3000.10.0 using Shell mode with default configurations are vulnerable.
💻 Affected Systems
- OliveTin
📦 What is this software?
Olivetin by Olivetin
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to execute arbitrary commands with OliveTin process privileges, potentially leading to data theft, lateral movement, or ransomware deployment.
Likely Case
Attackers exploiting webhook functionality to gain unauthenticated RCE on internet-facing instances, then establishing persistence and exploring the network.
If Mitigated
Limited impact if authentication is required and webhooks are disabled, though authenticated users could still exploit vector 1.
🎯 Exploit Status
Two independent exploitation vectors exist, with vector 2 allowing unauthenticated RCE via webhooks. The vulnerability is straightforward to exploit given the public advisory details.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not available
Vendor Advisory: https://github.com/OliveTin/OliveTin/security/advisories/GHSA-49gm-hh7w-wfvf
Restart Required: Yes
Instructions:
No official patch available. Monitor the GitHub advisory for updates and apply immediately when released.
🔧 Temporary Workarounds
Disable Shell Mode
allDisable Shell mode entirely to prevent command injection via both vectors
Edit OliveTin configuration to remove or disable shell actions
Require Authentication
allEnable authentication and disable user registration
Set authType to 'basic' or 'oidc' in config.yaml
Set allowUserRegistration: false
Disable Webhooks
allPrevent unauthenticated RCE by disabling webhook functionality
Remove or disable webhook-triggered actions in configuration
🧯 If You Can't Patch
- Immediately disable OliveTin instances or restrict network access to trusted IPs only
- Implement strict network segmentation to isolate OliveTin from critical systems
🔍 How to Verify
Check if Vulnerable:
Check OliveTin version and configuration. If version ≤ 3000.10.0 and using Shell mode, assume vulnerable.Check Version:
Check OliveTin web interface or configuration files for version informationVerify Fix Applied:
When patch becomes available, verify version is > 3000.10.0 and test that password arguments and webhook values are properly sanitized.📡 Detection & Monitoring
Log Indicators:
- Unusual shell commands executed by OliveTin process
- Webhook requests with suspicious JSON payloads
- Authentication attempts from unexpected sources
Network Indicators:
- Outbound connections from OliveTin host to suspicious destinations
- Unusual process spawning patterns
SIEM Query:
Process execution where parent_process contains 'OliveTin' AND command_line contains suspicious patterns like 'curl', 'wget', 'bash -c', or 'sh -c'