CVE-2005-4746 in FreeRADIUS
Summary
by MITRE
Multiple buffer overflows in FreeRADIUS 1.0.3 and 1.0.4 allow remote attackers to cause denial of service (crash) via (1) the rlm_sqlcounter module or (2) unknown vectors "while expanding %t".
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Analysis
by VulDB Data Team • 07/25/2019
The vulnerability identified as CVE-2005-4746 represents a critical security flaw affecting FreeRADIUS versions 1.0.3 and 1.0.4, specifically targeting buffer overflow conditions that can be exploited remotely to execute denial of service attacks. This issue stems from inadequate input validation and memory management practices within the radius server implementation, creating exploitable conditions that can be leveraged by unauthorized actors to disrupt network authentication services. The vulnerability manifests in two distinct attack vectors, with the first vector affecting the rlm_sqlcounter module and the second vector involving unknown conditions during the expansion of the %t parameter, both of which demonstrate the susceptibility of the FreeRADIUS server to memory corruption attacks.
The technical exploitation of this vulnerability occurs through buffer overflow conditions that can be triggered when the FreeRADIUS server processes specific input parameters. The rlm_sqlcounter module vulnerability suggests that database query processing within the authentication framework contains insufficient bounds checking, allowing attackers to provide malicious input that exceeds allocated buffer sizes. The second vector involving %t parameter expansion indicates that the server's string expansion mechanism lacks proper input sanitization, potentially allowing crafted payloads to overwrite adjacent memory locations. These buffer overflow conditions directly correlate to CWE-121, which describes heap-based buffer overflow conditions, and CWE-122, which addresses stack-based buffer overflows, both of which are fundamental memory safety issues that can lead to arbitrary code execution or system crashes.
The operational impact of CVE-2005-4746 extends beyond simple service disruption, as the denial of service conditions can severely compromise network infrastructure security. When exploited, these vulnerabilities can cause FreeRADIUS servers to crash and restart automatically, creating authentication service outages that can affect thousands of users depending on the network environment. In enterprise settings, this vulnerability poses significant risks to network access control systems, potentially allowing attackers to maintain persistent access to network resources while disrupting legitimate authentication processes. The vulnerability aligns with ATT&CK technique T1499.004, which covers network denial of service attacks, and demonstrates how authentication infrastructure can be targeted to undermine network security posture. Organizations relying on FreeRADIUS for network access control, VPN authentication, or wireless network security may experience cascading failures as authentication services become unavailable.
Mitigation strategies for CVE-2005-4746 require immediate implementation of version upgrades to FreeRADIUS 1.0.5 or later, which contain patches addressing the identified buffer overflow conditions. System administrators should also implement network monitoring to detect unusual authentication service behavior that may indicate exploitation attempts, while applying input validation measures to restrict malformed requests before they reach the vulnerable modules. The implementation of intrusion detection systems can help identify patterns associated with buffer overflow exploitation attempts, and network segmentation can limit the scope of potential attacks. Additionally, organizations should conduct thorough vulnerability assessments of their authentication infrastructure to identify any other potentially vulnerable components and ensure that all FreeRADIUS installations are updated to secure versions. The remediation process should include comprehensive testing of updated configurations to ensure that authentication services continue to function correctly after patch application, while maintaining proper logging and audit trails to monitor for any residual vulnerabilities.