CVE-2023-4612 in CAS
Summary
by MITRE • 11/09/2023
Improper Authentication vulnerability in Apereo CAS in jakarta.servlet.http.HttpServletRequest.getRemoteAddr method allows Multi-Factor Authentication bypass.This issue affects CAS: through 7.0.0-RC7. It is unknown whether in new versions the issue will be fixed. For the date of publication there is no patch, and the vendor does not treat it as a vulnerability.
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Analysis
by VulDB Data Team • 10/10/2024
The CVE-2023-4612 vulnerability represents a critical improper authentication flaw within the Apereo CAS (Central Authentication Service) platform that specifically targets the jakarta.servlet.http.HttpServletRequest.getRemoteAddr method. This vulnerability occurs within CAS versions through 7.0.0-RC7 and creates a significant security risk by potentially allowing attackers to bypass multi-factor authentication mechanisms. The flaw exploits the way CAS handles remote address detection during authentication processes, creating a pathway for unauthorized access that undermines the security controls designed to protect sensitive systems. The vulnerability's impact is particularly concerning given that CAS serves as a widely-deployed single sign-on solution in enterprise and academic environments where security is paramount.
The technical implementation of this vulnerability stems from how the getRemoteAddr method is utilized within the authentication flow of CAS. When CAS processes authentication requests, it relies on the remote address information to make decisions about authentication strength and security measures. However, the flawed implementation allows for manipulation of this address information, potentially enabling attackers to present false IP addresses that bypass the multi-factor authentication requirements. This misconfiguration creates an authentication bypass scenario where legitimate users may be required to provide additional authentication factors while malicious actors can exploit the vulnerability to gain access without proper verification. The flaw operates at the network layer where address information is processed, making it particularly difficult to detect and mitigate through traditional security measures.
The operational impact of this vulnerability extends beyond simple authentication bypasses to potentially compromise entire authentication ecosystems within organizations using CAS. Attackers who successfully exploit this vulnerability could gain unauthorized access to protected resources, potentially leading to data breaches, privilege escalation, and unauthorized system modifications. The vulnerability affects the fundamental security model of CAS by undermining the trust assumptions that are made about remote address information. Organizations relying on CAS for secure authentication may experience unauthorized access to sensitive applications and services, particularly those that depend on multi-factor authentication for protection. The lack of a vendor patch and the vendor's non-acknowledgment of the issue creates additional operational challenges for security teams who must implement workarounds or alternative security measures.
Security professionals should consider this vulnerability in the context of broader authentication attack patterns and the specific weaknesses it exposes in the CAS framework. The issue aligns with common attack vectors described in the MITRE ATT&CK framework under credential access and privilege escalation techniques, where attackers manipulate authentication mechanisms to gain unauthorized access. Organizations should implement network-level controls and monitoring to detect anomalous authentication patterns that might indicate exploitation attempts. The vulnerability also relates to CWE-287, which describes improper authentication issues in software systems, highlighting the need for robust authentication validation mechanisms. Given the absence of official patches and vendor acknowledgment, security teams must develop defensive strategies including network segmentation, enhanced monitoring of authentication logs, and implementation of additional verification mechanisms that do not rely on the vulnerable remote address detection methods. The vulnerability underscores the importance of maintaining vigilance in authentication system security and the need for proactive security measures when vendors do not promptly address identified issues.