CVE-2017-2292
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary code on MCollective servers by sending specially crafted YAML payloads. It affects all MCollective versions before 2.10.4 that use third-party plugins or custom code. Organizations using Puppet's MCollective orchestration framework are at risk.
💻 Affected Systems
- MCollective
- Puppet Enterprise (if using MCollective)
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of MCollective servers leading to lateral movement across infrastructure, data theft, and persistent backdoor installation.
Likely Case
Unauthorized code execution on MCollective servers allowing attackers to manipulate Puppet-managed infrastructure, steal credentials, or disrupt operations.
If Mitigated
Limited impact with proper network segmentation and strict plugin validation, though risk remains if vulnerable plugins are used.
🎯 Exploit Status
Exploitation requires sending malicious YAML to MCollective agents. The vulnerability is well-documented and similar to other YAML deserialization issues.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.10.4 and later
Vendor Advisory: https://puppet.com/security/cve/cve-2017-2292
Restart Required: Yes
Instructions:
1. Update MCollective to version 2.10.4 or later. 2. Update all third-party plugins to versions that use YAML.safe_load. 3. Restart MCollective services. 4. Verify no custom code uses unsafe YAML loading.
🔧 Temporary Workarounds
Disable vulnerable plugins
allIdentify and disable any third-party plugins that might use unsafe YAML deserialization
# Check plugin configurations
# Disable suspicious plugins in mcollective configuration
Network segmentation
linuxRestrict network access to MCollective servers to trusted hosts only
# Configure firewall rules
iptables -A INPUT -p tcp --dport 61613 -s trusted_network -j ACCEPT
iptables -A INPUT -p tcp --dport 61613 -j DROP
🧯 If You Can't Patch
- Implement strict network controls to limit access to MCollective servers
- Audit and remove all third-party plugins, using only Puppet-supplied plugins
🔍 How to Verify
Check if Vulnerable:
Check MCollective version: mco --version. If version is below 2.10.4, the system is vulnerable.Check Version:
mco --versionVerify Fix Applied:
Verify version is 2.10.4 or higher and check that YAML.safe_load is used in all plugin code.📡 Detection & Monitoring
Log Indicators:
- Unusual YAML parsing errors in MCollective logs
- Suspicious plugin activation patterns
- Unexpected code execution attempts
Network Indicators:
- Unusual traffic to MCollective port (typically 61613)
- Malformed YAML payloads in network captures
SIEM Query:
source="mcollective.log" AND ("YAML" OR "deserialization" OR "unsafe_load")