CVE-2003-0058 in Kerberos
Summary
by MITRE
MIT Kerberos V5 Key Distribution Center (KDC) before 1.2.5 allows remote authenticated attackers to cause a denial of service (crash) on KDCs within the same realm via a certain protocol request that causes a null dereference.
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Analysis
by VulDB Data Team • 08/25/2025
The vulnerability identified as CVE-2003-0058 represents a critical denial of service flaw within the MIT Kerberos V5 Key Distribution Center implementation. This vulnerability specifically affects KDC versions prior to 1.2.5 and stems from improper handling of certain protocol requests that result in a null pointer dereference condition. The flaw occurs when authenticated attackers within the same Kerberos realm submit malicious protocol requests that trigger the KDC to attempt to dereference a null pointer, leading to an immediate crash of the key distribution center service.
The technical nature of this vulnerability aligns with CWE-476, which categorizes null pointer dereference conditions as a common programming error that can lead to system instability and service disruption. The vulnerability operates at the protocol level within the Kerberos authentication framework, specifically targeting the KDC's response handling mechanism. When the KDC receives a malformed request that contains unexpected null values in critical data structures, the application fails to properly validate these inputs before attempting to access the referenced memory locations, resulting in an unhandled exception that terminates the service process.
From an operational perspective, this vulnerability poses significant risks to organizations relying on Kerberos authentication for secure network access and service authorization. The attack requires only authenticated access within the same realm, making it particularly dangerous as it can be exploited by compromised accounts or insider threats. The impact extends beyond simple service disruption, as the KDC is a critical component in Kerberos infrastructure that serves as the central authority for authentication and ticket granting services. When the KDC crashes, all services dependent on Kerberos authentication become inaccessible, potentially affecting multiple systems and applications across the network infrastructure.
The exploitation of this vulnerability follows patterns consistent with ATT&CK technique T1499.004, which involves network denial of service attacks targeting critical infrastructure components. Organizations implementing Kerberos-based authentication systems must consider this vulnerability as part of their broader security posture assessment, particularly in environments where the KDC serves as a primary authentication authority. The flaw demonstrates the importance of proper input validation and error handling in security-critical applications, as even authenticated users can potentially disrupt service availability through carefully crafted protocol requests.
Mitigation strategies for CVE-2003-0058 should prioritize immediate patching of affected KDC implementations to version 1.2.5 or later, which includes proper null pointer validation and error handling mechanisms. System administrators should also implement monitoring solutions to detect unusual patterns of authentication requests that might indicate attempted exploitation, while maintaining robust backup and recovery procedures for KDC services. Network segmentation and access control measures can help limit the potential impact of such attacks by restricting unauthorized access to Kerberos realms. Additionally, organizations should conduct regular security assessments of their authentication infrastructure to identify and remediate similar vulnerabilities that may exist in other components of their security ecosystem, ensuring comprehensive protection against both external and internal threats targeting critical authentication services.