CVE-2019-1851 Explained : Impact and Mitigation
Learn about CVE-2019-1851, a vulnerability in Cisco Identity Services Engine allowing attackers to create unauthorized certificates. Find mitigation steps and patching advice here.
Cisco Identity Services Engine Arbitrary Client Certificate Creation Vulnerability
Understanding CVE-2019-1851
This CVE involves a weakness in the External RESTful Services (ERS) API of the Cisco Identity Services Engine (ISE) that allows an authenticated attacker to create custom certificates signed by the Internal Certificate Authority (CA) Services on ISE.
What is CVE-2019-1851?
The vulnerability stems from an inaccurate implementation of role-based access control (RBAC) within the ISE, enabling an attacker with administrative credentials to craft a specific HTTP request to generate a trusted certificate signed by the ISE CA.
The Impact of CVE-2019-1851
If successfully exploited, the attacker can produce a certificate with arbitrary attributes, granting unauthorized access to networks or assets protected by certificate authentication.
Technical Details of CVE-2019-1851
Vulnerability Description
- Vulnerability Type: CWE-285
- Weakness in ERS API of Cisco ISE
- Allows creation of unauthorized certificates
Affected Systems and Versions
- Product: Cisco Identity Services Engine Software
- Vendor: Cisco
- Version: Unspecified
Exploitation Mechanism
- Attacker needs administrative credentials
- Craft specific HTTP request to generate a trusted certificate
Mitigation and Prevention
Immediate Steps to Take
- Apply vendor-provided patches promptly
- Monitor network for any unauthorized certificate creation
- Restrict access to administrative credentials
Long-Term Security Practices
- Regular security training for staff on RBAC best practices
- Implement network segmentation to limit certificate access
Patching and Updates
- Regularly check for security advisories from Cisco
- Apply recommended patches and updates as soon as they are available