CVE-2013-6800 in Kerberos
Summary
by MITRE
An unspecified third-party database module for the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) 1.10.x allows remote authenticated users to cause a denial of service (NULL pointer dereference and daemon crash) via a crafted request, a different vulnerability than CVE-2013-1418.
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Analysis
by VulDB Data Team • 06/02/2021
The vulnerability identified as CVE-2013-6800 represents a critical denial of service weakness within the MIT Kerberos 5 implementation, specifically affecting the Key Distribution Center component that serves as the central authentication authority in kerberos environments. This flaw exists within a third-party database module integrated into the KDC functionality, making it particularly concerning as it operates at a fundamental level of the authentication infrastructure that countless organizations depend upon for secure network access and service authentication.
The technical nature of this vulnerability manifests through a NULL pointer dereference condition that occurs when the KDC processes a specially crafted request from an authenticated remote user. This particular flaw differs from CVE-2013-1418, indicating it operates through a distinct code path within the database module component. The vulnerability exploits a condition where the system attempts to access memory through a null pointer reference, causing the KDC daemon to crash and terminate its operations entirely. This behavior aligns with CWE-476 which categorizes NULL pointer dereference as a common programming error that can lead to application instability and system unavailability.
The operational impact of this vulnerability extends beyond simple service disruption as it affects the core authentication infrastructure that many enterprise systems rely upon. When the KDC daemon crashes, all authentication services that depend on it become unavailable, potentially affecting thousands of users and systems simultaneously across an organization. The fact that this vulnerability requires only authenticated access makes it particularly dangerous as it can be exploited by malicious insiders or compromised accounts, creating a scenario where an attacker with legitimate credentials can cause widespread service disruption.
Organizations implementing MIT Kerberos 5 versions 1.10.x should prioritize immediate remediation through official security patches provided by the MIT Kerberos team. The vulnerability's classification as a denial of service issue means that traditional network security controls may not prevent exploitation, as the attack vector involves legitimate authenticated users. System administrators should implement monitoring for unusual authentication patterns that might indicate exploitation attempts, while also ensuring proper access controls and account management practices to limit the potential impact of compromised credentials. This vulnerability demonstrates the critical importance of maintaining up-to-date authentication infrastructure and highlights the need for comprehensive security testing of third-party components integrated into core security services. The attack pattern associated with this vulnerability aligns with tactics described in the MITRE ATT&CK framework under the denial of service category, where adversaries leverage application-level weaknesses to disrupt system availability.