CVE-2014-3527 in Spring Security
Summary
by MITRE
When using the CAS Proxy ticket authentication from Spring Security 3.1 to 3.2.4 a malicious CAS Service could trick another CAS Service into authenticating a proxy ticket that was not associated. This is due to the fact that the proxy ticket authentication uses the information from the HttpServletRequest which is populated based upon untrusted information within the HTTP request. This means if there are access control restrictions on which CAS services can authenticate to one another, those restrictions can be bypassed. If users are not using CAS Proxy tickets and not basing access control decisions based upon the CAS Service, then there is no impact to users.
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Analysis
by VulDB Data Team • 12/16/2024
The vulnerability described in CVE-2014-3527 represents a critical authentication bypass issue within the Central Authentication Service (CAS) proxy ticket implementation in Spring Security versions 3.1 through 3.2.4. This flaw stems from improper validation of request parameters that are directly sourced from the HttpServletRequest object, which contains untrusted data from HTTP requests. The vulnerability specifically affects the proxy ticket authentication mechanism where one CAS service attempts to authenticate another CAS service using proxy tickets. The core technical issue occurs because the system relies on information extracted from the HTTP request without adequate sanitization or validation, allowing malicious actors to manipulate the authentication flow. This weakness creates a path for attackers to forge proxy ticket authentications that should not be valid, effectively undermining the security model of the CAS system.
The operational impact of this vulnerability is significant as it enables attackers to bypass access control restrictions that are supposed to prevent unauthorized CAS service-to-service authentication. When CAS services implement access controls to determine which services can authenticate to others, this vulnerability allows malicious actors to circumvent those protections entirely. The flaw essentially allows a compromised CAS service to authenticate proxy tickets on behalf of other services without proper authorization, potentially leading to unauthorized access to protected resources. The vulnerability is particularly dangerous because it operates at the authentication layer, meaning successful exploitation could result in full system compromise if the authenticated services have elevated privileges or access to sensitive data. According to CWE-284, this represents an improper access control issue where the system fails to properly validate the authenticity of proxy ticket requests, while the ATT&CK framework would classify this under privilege escalation techniques that exploit authentication bypass vulnerabilities.
Organizations using Spring Security versions within the affected range must implement immediate mitigations to protect their CAS infrastructure. The primary solution involves upgrading to a patched version of Spring Security where the HttpServletRequest parameters are properly validated and sanitized before being used in proxy ticket authentication decisions. Additionally, administrators should implement additional layers of validation beyond the default CAS proxy ticket mechanism, including stricter access control policies that verify service identities through multiple authentication factors. Network-level controls such as firewall rules that restrict direct communication between CAS services and implementing service identity verification tokens can provide additional protection. The vulnerability demonstrates the importance of input validation and the principle of least privilege in authentication systems, as outlined in security best practices for web application development. Organizations should also conduct thorough security assessments of their CAS implementations to identify any other potential authentication bypass opportunities that could be exploited through similar vector attacks.