CVE-2005-1174 in Kerberos
Summary
by MITRE
MIT Kerberos 5 (krb5) 1.3 through 1.4.1 Key Distribution Center (KDC) allows remote attackers to cause a denial of service (application crash) via a certain valid TCP connection that causes a free of unallocated memory.
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Analysis
by VulDB Data Team • 07/04/2025
The vulnerability identified as CVE-2005-1174 affects MIT Kerberos 5 versions 1.3 through 1.4.1, specifically within the Key Distribution Center component that serves as the central authentication server in Kerberos network authentication systems. This flaw represents a classic memory corruption issue that can be exploited by remote attackers to disrupt service availability. The vulnerability occurs when the KDC processes a valid TCP connection that triggers improper memory management operations, leading to application instability and potential system crashes. The affected KDC service operates as a critical infrastructure component in enterprise environments relying on Kerberos authentication protocols, making this vulnerability particularly concerning for organizations dependent on secure network authentication mechanisms.
The technical root cause of this vulnerability stems from improper memory handling within the KDC's TCP connection processing logic. When a specially crafted valid TCP connection is established with the KDC service, the system attempts to free memory that has not been properly allocated or has already been deallocated, resulting in a memory corruption condition. This type of vulnerability falls under the CWE-415 category of double free errors or more broadly memory management flaws that can lead to application crashes and system instability. The flaw demonstrates a lack of proper input validation and memory allocation tracking within the Kerberos KDC implementation, where the service fails to properly manage memory resources during connection handling operations.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the security posture of affected organizations. Remote attackers can exploit this vulnerability to perform denial of service attacks against Kerberos KDC services without requiring authentication credentials, making it particularly dangerous in enterprise environments where Kerberos is used for critical authentication services. When the KDC service crashes due to this memory corruption, it can result in widespread authentication failures across the network, affecting numerous services and applications that depend on Kerberos for secure authentication. The vulnerability affects the availability aspect of the CIA security triad, potentially disrupting business operations and creating opportunities for more sophisticated attacks targeting the compromised authentication infrastructure.
Organizations affected by this vulnerability should prioritize immediate remediation through patching the MIT Kerberos 5 software to versions 1.4.2 or later where this memory management issue has been addressed. System administrators should also implement network monitoring to detect unusual connection patterns that might indicate exploitation attempts against the KDC service. The vulnerability aligns with ATT&CK technique T1499.004 for network denial of service attacks and represents a classic example of how memory corruption vulnerabilities can be leveraged to achieve service disruption. Additionally, organizations should consider implementing network segmentation to limit exposure of KDC services to untrusted networks and establish robust monitoring for abnormal service behavior. Regular security assessments and vulnerability scanning should include verification of Kerberos service versions to ensure all systems are properly updated and protected against this and similar memory management flaws that could potentially be exploited for more severe security incidents.