CVE-2004-0576 in Radius
Summary
by MITRE
the radius daemon (radiusd) for gnu radius 1.1 when compiled with the -enable-snmp option allows remote attackers to cause a denial of service (server crash) via malformed snmp messages containing an invalid oid.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 06/22/2018
The vulnerability identified as CVE-2004-0576 affects the GNU RADIUS daemon version 1.1 when compiled with the -enable-snmp option, presenting a significant security risk that can be exploited by remote attackers to cause a denial of service condition. This issue stems from inadequate input validation within the SNMP message processing functionality of the RADIUS daemon, specifically when handling malformed SNMP packets containing invalid object identifiers. The vulnerability represents a classic buffer overflow scenario where the daemon fails to properly validate SNMP message structures before processing them, leading to potential server crashes and service disruption.
The technical flaw manifests when the radius daemon receives SNMP messages with malformed object identifiers that do not conform to the standard SNMP protocol specifications. When the daemon attempts to process these invalid OIDs, the lack of proper validation mechanisms causes the application to crash or become unresponsive, effectively rendering the RADIUS service unavailable to legitimate users. This type of vulnerability falls under CWE-121, which describes stack-based buffer overflow conditions, and also relates to CWE-122, heap-based buffer overflow, depending on the specific memory corruption patterns observed during exploitation. The vulnerability exists because the SNMP processing code does not perform adequate bounds checking or input sanitization before attempting to parse and process the object identifier components.
From an operational standpoint, this vulnerability presents a serious threat to network infrastructure security as it allows remote attackers to disrupt critical authentication services. The RADIUS protocol serves as a fundamental component in network access control, managing user authentication, authorization, and accounting for network resources. When the radius daemon crashes due to malformed SNMP messages, network administrators lose access to centralized authentication services, potentially affecting thousands of users and devices across the network. The impact extends beyond simple service disruption as it can compromise network security posture by removing the ability to authenticate users and control access to protected resources. Attackers can exploit this vulnerability without requiring authentication credentials, making it particularly dangerous in environments where network access control is critical for security operations.
The exploitation of this vulnerability aligns with ATT&CK technique T1499.004, which describes network denial of service attacks targeting network infrastructure services. The attack vector involves sending specially crafted SNMP packets to the affected RADIUS daemon, which then processes these malformed messages and crashes. This vulnerability demonstrates the importance of input validation in network services and highlights how seemingly minor implementation flaws in protocol handling can lead to significant service disruptions. Organizations should implement network segmentation and access controls to limit exposure to such attacks, while also ensuring that network services are regularly updated and patched to address known vulnerabilities. The recommended mitigation strategies include disabling the SNMP functionality in the RADIUS daemon when it is not required, applying the appropriate software patches, and implementing network monitoring to detect and block suspicious SNMP traffic patterns that may indicate exploitation attempts.
The broader implications of this vulnerability extend to the need for comprehensive security testing of network infrastructure services, particularly those that handle external communications. The issue demonstrates how legacy code and optional features can introduce unexpected security risks when not properly validated against standard protocol specifications. Network security professionals should consider implementing intrusion detection systems that can identify malformed SNMP traffic patterns and automatically block suspicious communications. Additionally, regular security assessments of network infrastructure components should include thorough testing of protocol handling functions to identify similar vulnerabilities that could lead to service disruption or system compromise. The vulnerability serves as a reminder that even minor features like SNMP integration can pose significant security risks if not properly implemented and validated against industry standards and best practices.