CVE-2019-1010306
📋 TL;DR
CVE-2019-1010306 is a critical remote code execution vulnerability in Slanger 0.6.0 that allows unauthenticated attackers to execute arbitrary commands on affected servers by sending specially crafted requests. The vulnerability exists in the message handler and request validator components. Any organization running vulnerable Slanger instances is affected.
💻 Affected Systems
- Slanger
📦 What is this software?
Slanger by Teller
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to execute arbitrary commands, steal data, install malware, pivot to other systems, and maintain persistent access.
Likely Case
Attackers gain shell access to the server, potentially compromising sensitive data and using the system as a foothold for further attacks.
If Mitigated
If properly segmented and monitored, impact could be limited to the Slanger service container with minimal lateral movement.
🎯 Exploit Status
The vulnerability is in the request validation logic, making exploitation straightforward for attackers with network access.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: After commit 5267b455caeb2e055cccf0d2b6a22727c111f5c3
Vendor Advisory: https://github.com/stevegraham/slanger/pull/238/commits/5267b455caeb2e055cccf0d2b6a22727c111f5c3
Restart Required: Yes
Instructions:
1. Update Slanger to a version after commit 5267b455caeb2e055cccf0d2b6a22727c111f5c3. 2. Restart the Slanger service. 3. Verify the fix is applied by checking the version.
🔧 Temporary Workarounds
Network Segmentation
linuxRestrict network access to Slanger instances using firewall rules
iptables -A INPUT -p tcp --dport [SLANGER_PORT] -s [TRUSTED_NETWORK] -j ACCEPT
iptables -A INPUT -p tcp --dport [SLANGER_PORT] -j DROP
🧯 If You Can't Patch
- Immediately isolate vulnerable Slanger instances from the internet and untrusted networks
- Implement strict network monitoring and IDS/IPS rules to detect exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check if running Slanger version 0.6.0. If version cannot be determined, check if the code includes the vulnerable request validation logic.Check Version:
Check Slanger startup logs or configuration files for version information. For Ruby applications: `bundle show slanger` or check Gemfile.lock.Verify Fix Applied:
Verify the Slanger version is after commit 5267b455caeb2e055cccf0d2b6a22727c111f5c3 and test with known exploit payloads to ensure they are rejected.📡 Detection & Monitoring
Log Indicators:
- Unusual request patterns to Slanger endpoints
- Error messages related to request validation failures
- Unexpected process spawns from Slanger
Network Indicators:
- Malformed WebSocket or HTTP requests to Slanger ports
- Unusual outbound connections from Slanger servers
SIEM Query:
source="slanger.log" AND ("malformed" OR "validation" OR "unexpected") OR process_name="slanger" AND parent_process!="expected_parent"