CVE-2021-3584
📋 TL;DR
CVE-2021-3584 is a server-side remote code execution vulnerability in Foreman that allows authenticated attackers to inject malicious commands through Sendmail configuration options. This enables attackers to execute arbitrary code on the Foreman server with the privileges of the Foreman service. Organizations running vulnerable versions of Foreman with authenticated user access are affected.
💻 Affected Systems
- Foreman
📦 What is this software?
Foreman by Theforeman
Foreman by Theforeman
Foreman by Theforeman
Foreman by Theforeman
Satellite by Redhat
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise allowing attacker to execute arbitrary commands as the Foreman service user, potentially leading to data exfiltration, lateral movement, or complete system takeover.
Likely Case
Unauthorized command execution leading to configuration changes, data manipulation, or installation of backdoors on the Foreman server.
If Mitigated
Limited impact due to network segmentation, minimal user privileges, and proper input validation controls.
🎯 Exploit Status
Exploitation requires authenticated access but the vulnerability is straightforward to exploit once authenticated.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.4.1, 2.5.1, or 3.0.0
Vendor Advisory: https://projects.theforeman.org/issues/32753
Restart Required: Yes
Instructions:
1. Backup Foreman configuration and data. 2. Update Foreman to version 2.4.1, 2.5.1, or 3.0.0 using your package manager. 3. Restart Foreman services. 4. Verify the update was successful.
🔧 Temporary Workarounds
Restrict Sendmail Configuration Access
linuxLimit user permissions to prevent modification of Sendmail configuration options
# Review and modify Foreman role permissions to restrict Sendmail configuration access
Network Segmentation
allIsolate Foreman server from critical systems and limit network access
# Configure firewall rules to restrict access to Foreman server
🧯 If You Can't Patch
- Implement strict access controls and least privilege principles for Foreman users
- Monitor and audit all user activities related to Sendmail configuration changes
🔍 How to Verify
Check if Vulnerable:
Check Foreman version: if running version before 2.4.1, 2.5.1, or 3.0.0, the system is vulnerable.Check Version:
foreman --versionVerify Fix Applied:
Verify Foreman version is 2.4.1, 2.5.1, or 3.0.0 or later, and test that Sendmail configuration options properly validate input.📡 Detection & Monitoring
Log Indicators:
- Unusual command execution in Foreman logs
- Unexpected modifications to Sendmail configuration
- Failed authentication attempts followed by configuration changes
Network Indicators:
- Unusual outbound connections from Foreman server
- Command and control traffic patterns
SIEM Query:
source="foreman.log" AND ("sendmail" OR "configuration") AND ("exec" OR "command" OR "inject")