CVE-2018-5506 Explained : Impact and Mitigation

CVE-2018-5506, published on April 12, 2018, addresses a vulnerability in F5 BIG-IP versions 13.0.0, 12.1.0-12.1.2, 11.6.1, 11.5.1-11.5.5, and 11.2.1. The issue allows unauthenticated bruteforce attacks on the em_server_ip authorization parameter, potentially exposing SSL client certificates used for mutual authentication.

Understanding CVE-2018-5506

This CVE entry highlights a security flaw in F5 BIG-IP products that could lead to information disclosure.

What is CVE-2018-5506?

The vulnerability in Apache modules apache_auth_token_mod and mod_auth_f5_auth_token.cpp enables unauthorized bruteforce attempts on em_server_ip, revealing SSL client certificates for mutual authentication.

The Impact of CVE-2018-5506

The exploit could allow malicious actors to extract sensitive SSL client certificate information, compromising the security of BIG-IQ or Enterprise Manager (EM) and associated BIG-IP devices.

Technical Details of CVE-2018-5506

This section delves into the specifics of the vulnerability.

Vulnerability Description

The flaw in F5 BIG-IP versions 13.0.0, 12.1.0-12.1.2, 11.6.1, 11.5.1-11.5.5, and 11.2.1 permits unauthenticated bruteforce attacks on the em_server_ip parameter, potentially exposing SSL client certificates.

Affected Systems and Versions

Products: BIG-IP (LTM, AAM, AFM, Analytics, APM, ASM, DNS, Edge Gateway, GTM, Link Controller, PEM, WebAccelerator, WebSafe)
Vendor: F5 Networks, Inc.
Vulnerable Versions: 13.0.0, 12.1.0-12.1.2, 11.6.1, 11.5.1-11.5.5, 11.2.1

Exploitation Mechanism

The vulnerability can be exploited using the Apache modules apache_auth_token_mod and mod_auth_f5_auth_token.cpp to perform unauthenticated bruteforce attacks on the em_server_ip parameter.

Mitigation and Prevention

Protecting systems from CVE-2018-5506 requires immediate actions and long-term security measures.

Immediate Steps to Take

Apply vendor-supplied patches promptly to mitigate the vulnerability.
Monitor network traffic for any suspicious activities related to SSL client certificate extraction.

Long-Term Security Practices

Regularly update and patch F5 BIG-IP devices to address security vulnerabilities promptly.
Implement strong authentication mechanisms and access controls to prevent unauthorized access.

Patching and Updates

Stay informed about security advisories from F5 Networks, Inc., and apply patches as soon as they are available to safeguard against potential exploits.