CVE-2008-0947 in Kerberos
Summary
by MITRE
Buffer overflow in the RPC library used by libgssrpc and kadmind in MIT Kerberos 5 (krb5) 1.4 through 1.6.3 allows remote attackers to execute arbitrary code by triggering a large number of open file descriptors.
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Analysis
by VulDB Data Team • 01/12/2025
The vulnerability described in CVE-2008-0947 represents a critical buffer overflow condition within the Remote Procedure Call (RPC) library implementation of MIT Kerberos 5 versions 1.4 through 1.6.3. This flaw exists in the gssrpc and kadmind components that form part of the Kerberos authentication framework widely deployed across enterprise networks and distributed systems. The vulnerability specifically manifests when the RPC library processes incoming requests that trigger an excessive number of open file descriptors, creating a scenario where memory boundaries are exceeded during buffer operations. This particular weakness falls under the CWE-121 buffer overflow category, where insufficient bounds checking allows attackers to overwrite adjacent memory locations and potentially execute malicious code with the privileges of the affected service.
The technical exploitation of this vulnerability requires remote attackers to craft specific RPC requests that cause the system to open an excessive number of file descriptors beyond the allocated buffer space. When the RPC library attempts to handle these requests, it fails to properly validate the number of file descriptors or the associated memory allocation, leading to a classic stack-based buffer overflow condition. The flaw is particularly dangerous because it can be triggered remotely without requiring authentication, making it an attractive target for attackers seeking to compromise Kerberos services. The vulnerability demonstrates a lack of proper input sanitization and resource management within the RPC processing pipeline, creating a pathway for arbitrary code execution that can potentially escalate privileges and allow full system compromise.
The operational impact of this vulnerability extends far beyond simple code execution, as Kerberos implementations serve as fundamental authentication services in many enterprise environments including active directory domains, network authentication systems, and distributed application frameworks. When exploited successfully, the vulnerability can result in complete system compromise of servers running affected Kerberos versions, potentially allowing attackers to gain unauthorized access to sensitive network resources, escalate privileges to administrative levels, and establish persistent backdoors within the network infrastructure. The attack vector is particularly concerning because it does not require authentication, meaning that any system running vulnerable versions of MIT Kerberos could be targeted by remote attackers. This vulnerability affects not only individual servers but also entire network authentication domains that depend on Kerberos for secure communication and access control.
Mitigation strategies for CVE-2008-0947 primarily involve immediate patching of affected systems with updated versions of MIT Kerberos that contain proper bounds checking and resource management controls. Organizations should prioritize updating all systems running krb5 versions 1.4 through 1.6.3 to the latest stable releases, which include fixes for the buffer overflow conditions in the RPC library. Network segmentation and firewall rules should be implemented to restrict unnecessary RPC traffic to affected services, while monitoring systems should be configured to detect anomalous file descriptor usage patterns that might indicate exploitation attempts. The vulnerability aligns with ATT&CK technique T1078 which covers valid accounts and privilege escalation, as successful exploitation can lead to unauthorized access and privilege elevation. Additionally, implementing proper input validation, resource limits, and regular security assessments can help prevent similar vulnerabilities from being exploited in the future, as this flaw demonstrates the critical importance of proper memory management and resource handling in authentication services.