CVE-2022-33968 in BIG-IP
Summary
by MITRE • 08/04/2022
In BIG-IP Versions 17.0.x before 17.0.0.1, 16.1.x before 16.1.3.1, 15.1.x before 15.1.6.1, 14.1.x before 14.1.5.1, and all versions of 13.1.x, when an LTM monitor or APM SSO is configured on a virtual server, and NTLM challenge-response is in use, undisclosed traffic can cause a buffer over-read. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
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Analysis
by VulDB Data Team • 08/30/2022
The vulnerability identified as CVE-2022-33968 affects F5 BIG-IP appliances across multiple version lines including 13.1.x, 14.1.x, 15.1.x, 16.1.x, and 17.0.x, specifically when certain monitoring and authentication configurations are implemented. This issue represents a critical buffer over-read condition that can be exploited through undisclosed traffic patterns, making it particularly dangerous as it may not be immediately apparent during normal network operations. The vulnerability manifests when LTM monitors or APM SSO configurations are active on virtual servers that utilize NTLM challenge-response authentication mechanisms.
The technical flaw stems from insufficient input validation within the BIG-IP appliance's handling of NTLM authentication traffic. When NTLM challenge-response is employed in conjunction with LTM monitors or APM SSO configurations, the system fails to properly validate buffer boundaries during traffic processing. This allows an attacker to craft malicious traffic that triggers a buffer over-read condition, potentially leading to memory corruption and system instability. The vulnerability is classified under CWE-125 as an "Out-of-bounds Read" and aligns with ATT&CK technique T1071.004 for application layer protocol manipulation. The buffer over-read occurs during the processing of NTLM authentication challenges, where the system attempts to read beyond allocated memory boundaries when handling malformed or unexpected NTLM traffic patterns.
The operational impact of this vulnerability extends beyond simple service disruption to potentially enable more sophisticated attacks including remote code execution and system compromise. Attackers can leverage this weakness to cause denial of service conditions that may result in complete system crashes or restarts, disrupting critical network services. The vulnerability's exploitation requires specific configuration conditions including active LTM monitors or APM SSO with NTLM authentication, making it more targeted but still potentially impactful for organizations with affected BIG-IP deployments. The undisclosed nature of the triggering traffic patterns means that detection is challenging and the vulnerability could remain undetected for extended periods within network environments.
Organizations should immediately implement mitigations including applying the latest security patches from F5 as referenced in their security advisory for this vulnerability. The recommended approach involves upgrading to the patched versions for each affected major release line, with the specific versions being 13.1.x patch releases, 14.1.5.1, 15.1.6.1, 16.1.3.1, and 17.0.0.1. Network segmentation and traffic monitoring should be enhanced to detect anomalous NTLM authentication patterns, while implementing firewall rules to restrict access to affected virtual servers. Additionally, organizations should conduct thorough vulnerability assessments to identify all affected BIG-IP appliances and implement proper access controls to limit exposure. The vulnerability's classification as a buffer over-read aligns with ATT&CK framework's focus on memory corruption techniques, indicating that defensive measures should include memory protection mechanisms and regular system integrity checks to prevent exploitation attempts.