CVE-2020-2021 Explained : Impact and Mitigation
Learn about CVE-2020-2021, an authentication bypass vulnerability in SAML on PAN-OS by Palo Alto Networks. Find impacted versions, exploitation details, and mitigation steps.
This CVE involves an authentication bypass vulnerability in SAML authentication on PAN-OS by Palo Alto Networks.
Understanding CVE-2020-2021
This vulnerability allows an unauthenticated attacker to access protected resources by exploiting improper signature verification in SAML authentication.
What is CVE-2020-2021?
When SAML authentication is enabled without validating the Identity Provider Certificate, attackers can gain unauthorized access to resources.
The Impact of CVE-2020-2021
- Severity: Critical with a CVSS Base Score of 10.0
- Affected Versions: PAN-OS 9.1.3 and earlier, 9.0.9 and earlier, 8.1.15 and earlier, and all versions of 8.0
- Attack Vector: Network-based
- Attack Complexity: Low
- Confidentiality and Integrity Impact: High
- Availability Impact: High
- No known malicious exploits
Technical Details of CVE-2020-2021
This section covers the vulnerability description, affected systems, exploitation mechanism, and mitigation steps.
Vulnerability Description
- Improper signature verification in SAML authentication on PAN-OS
- Allows unauthenticated attackers to access protected resources
Affected Systems and Versions
- PAN-OS 9.1.3 and earlier, 9.0.9 and earlier, 8.1.15 and earlier, and all versions of 8.0
Exploitation Mechanism
- Attacker needs network access to the vulnerable server
- Requires SAML authentication without validating the Identity Provider Certificate
Mitigation and Prevention
Steps to address and prevent exploitation of the vulnerability.
Immediate Steps to Take
- Ensure 'Validate Identity Provider Certificate' is enabled in SAML settings
- Use alternative authentication methods if possible
- Check and update SAML configurations on firewalls and Panorama
Long-Term Security Practices
- Regularly update PAN-OS to fixed versions (8.1.15, 9.0.9, 9.1.3, or later)
- Configure 'Identity Provider Certificate' for secure SAML authentication
- Monitor and clear unauthorized sessions in GlobalProtect and Captive Portal
Patching and Updates
- Upgrade to fixed PAN-OS versions to prevent future vulnerabilities
- Follow detailed upgrade instructions provided by Palo Alto Networks