1. Introduction
Ivanti Policy Secure is a VPN solution affected by a command injection vulnerability. This allows an unauthenticated attacker to execute arbitrary commands on the appliance, potentially compromising its confidentiality, integrity and availability. Systems running Ivanti Policy Secure 9.x or 22.x are typically affected.
2. Technical Explanation
The Ivanti Policy Secure web components contain a command injection vulnerability. An attacker can send specially crafted requests to the appliance which are not properly sanitised, leading to arbitrary command execution. This vulnerability is tracked as CVE-2024-21887. A realistic example would involve an attacker sending a malicious HTTP request containing shell commands within a vulnerable parameter.
- Root cause: Missing input validation in web components allows for the injection of OS commands.
- Exploit mechanism: An unauthenticated attacker sends crafted requests to execute arbitrary commands on the appliance.
- Scope: Ivanti Policy Secure versions 9.x and 22.x are affected.
3. Detection and Assessment
- Quick checks: Check the product version via the web interface or command line (if available).
- Scanning: Nessus ID 11330e19 can identify vulnerable instances. This is an example only, and other scanners may also be applicable.
- Logs and evidence: Review Ivanti Policy Secure logs for unusual process execution or network connections.
4. Solution / Remediation Steps
Apply the vendor-supplied patch to fix this issue. Follow these steps carefully.
4.1 Preparation
- Ensure a change window is scheduled and approved by relevant stakeholders.
4.2 Implementation
- Step 1: Apply the patch or upgrade to a fixed version of Ivanti Policy Secure as per vendor advisory.
4.3 Config or Code Example
Before
After
4.4 Security Practices Relevant to This Vulnerability
Several security practices can help prevent this type of issue.
- Practice 1: Input validation is crucial to block malicious data and prevent command injection attacks.
- Practice 2: Least privilege reduces the impact if an attacker gains access, limiting the scope of potential damage.
4.5 Automation (Optional)
5. Verification / Validation
- Post-fix check: Verify the Ivanti Policy Secure version is updated to a patched release.
- Re-test: Re-run the earlier detection method (e.g., Nessus scan) to confirm the vulnerability is no longer present.
- Smoke test: Test VPN connectivity and basic user authentication.
- Monitoring: Monitor Ivanti Policy Secure logs for any unusual activity or errors related to command execution. This is an example only, and specific log queries will vary.
6. Preventive Measures and Monitoring
Update security baselines and implement checks in CI/CD pipelines.
- Baselines: Update your security baseline to include the patched version of Ivanti Policy Secure.
- Pipelines: Add static or dynamic analysis tools to your CI/CD pipeline to detect similar vulnerabilities during development.
- Asset and patch process: Implement a regular patch review cycle for all critical systems, including Ivanti Policy Secure.
7. Risks, Side Effects, and Roll Back
Patching may cause temporary service disruption. A roll back plan involves restoring from backup.
- Risk or side effect 1: Patching could temporarily disrupt VPN connectivity. Mitigate by scheduling during off-peak hours.
- Roll back: Restore the Ivanti Policy Secure appliance configuration from the pre-patch backup.
8. References and Resources
- Vendor advisory or bulletin: http://www.nessus.org/u?11330e19
- NVD or CVE entry: CVE-2024-21887