CVE-2001-1081 in Radius
Summary
by MITRE
Format string vulnerabilities in Livingston/Lucent RADIUS before 2.1.va.1 may allow local or remote attackers to cause a denial of service and possibly execute arbitrary code via format specifiers that are injected into log messages.
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Analysis
by VulDB Data Team • 05/12/2019
The vulnerability identified as CVE-2001-1081 represents a critical format string flaw affecting Livingston/Lucent RADIUS servers prior to version 2.1.va.1. This issue stems from the improper handling of user-supplied input within log message generation processes, creating a pathway for malicious actors to inject format specifiers that can be exploited to manipulate program execution flow. The vulnerability exists in the authentication and accounting services that form the core of RADIUS protocol implementations, making it particularly dangerous in network security environments where these services are deployed.
Format string vulnerabilities occur when program input is directly used as a format string parameter without proper sanitization or validation. In this case, the Livingston/Lucent RADIUS implementation fails to properly escape or validate user-supplied data before incorporating it into log messages that utilize printf-style formatting functions. When attackers can control the input that gets processed through these vulnerable functions, they can exploit the format string functionality to read from or write to arbitrary memory locations, potentially leading to privilege escalation or arbitrary code execution. The vulnerability affects both local and remote attack vectors, as user input can be injected through RADIUS authentication requests or accounting messages that are processed by the vulnerable server.
The operational impact of this vulnerability extends beyond simple denial of service conditions to potentially enable complete system compromise. Attackers exploiting this flaw could execute arbitrary code with the privileges of the RADIUS server process, which typically runs with elevated permissions to manage network access controls. This could result in unauthorized network access, data exfiltration, or the establishment of persistent backdoors within the network infrastructure. The vulnerability's presence in RADIUS servers is particularly concerning as these services often serve as critical components in enterprise network security frameworks, controlling access to network resources for thousands of users. The attack surface is further expanded by the fact that RADIUS servers are commonly deployed in environments where they must accept input from multiple sources, including potentially untrusted network devices and authentication clients.
Mitigation strategies for CVE-2001-1081 should prioritize immediate patching of affected Livingston/Lucent RADIUS installations to version 2.1.va.1 or later, which contains the necessary fixes to properly sanitize input before log message generation. Organizations should implement network segmentation to limit access to RADIUS servers and employ intrusion detection systems to monitor for potential exploitation attempts. Input validation and sanitization measures should be strengthened throughout the application to prevent format string injection, with particular attention to log message construction. Security monitoring should include detection of unusual log message patterns that might indicate format string exploitation attempts, and system administrators should regularly audit RADIUS server configurations to ensure proper input handling. This vulnerability aligns with CWE-134 which specifically addresses format string vulnerabilities, and maps to ATT&CK techniques involving privilege escalation and code execution through software vulnerabilities. The remediation process should also include comprehensive security testing of all network authentication services to identify similar vulnerabilities in other components of the network infrastructure.