CVE-2011-0282 in Kerberos
Summary
by MITRE
The Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) 1.6.x through 1.9, when an LDAP backend is used, allows remote attackers to cause a denial of service (NULL pointer dereference or buffer over-read, and daemon crash) via a crafted principal name.
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Analysis
by VulDB Data Team • 12/29/2024
The vulnerability identified as CVE-2011-0282 represents a critical denial of service weakness within the Key Distribution Center component of MIT Kerberos 5 versions 1.6 through 1.9 when configured with an LDAP backend. This flaw resides in the authentication infrastructure that many organizations rely upon for secure network communications and identity management. The vulnerability specifically manifests when the KDC processes principal names through LDAP backends, creating a pathway for remote attackers to disrupt service availability.
The technical implementation of this vulnerability stems from inadequate input validation within the KDC's LDAP backend processing logic. When a maliciously crafted principal name is submitted, the system fails to properly handle edge cases in the name parsing routine, leading to either a NULL pointer dereference or a buffer over-read condition. These memory corruption issues occur during the LDAP backend interaction where the KDC attempts to process and validate principal identifiers. The flaw operates at the application layer and requires no authentication to exploit, making it particularly dangerous as it can be triggered by any remote attacker with network access to the KDC service.
The operational impact of this vulnerability extends beyond simple service disruption, as it can cause complete daemon crashes that require manual intervention to restore. Organizations utilizing Kerberos with LDAP backends face potential service outages that can affect authentication services across their entire network infrastructure. This vulnerability directly impacts the availability aspect of the CIA triad, potentially leaving systems unable to authenticate users or provide secure access controls. The crash condition can affect not only individual KDC instances but may also propagate to dependent services that rely on Kerberos authentication, creating cascading failures throughout the authenticated network environment.
Mitigation strategies for CVE-2011-0282 should prioritize immediate patching of affected Kerberos versions to the latest stable releases that contain the necessary input validation fixes. Organizations should also consider implementing network segmentation to limit exposure of KDC services to untrusted networks and deploy monitoring solutions that can detect unusual authentication patterns or service disruptions. Additionally, administrators should review and test their LDAP backend configurations to ensure proper input sanitization and implement redundant KDC services where possible. This vulnerability aligns with CWE-125 for buffer over-read conditions and CWE-476 for NULL pointer dereferences, while also mapping to ATT&CK technique T1499 for network denial of service attacks. The remediation process should include thorough testing of patched systems to ensure that the fix does not introduce compatibility issues with existing LDAP directory structures or authentication workflows.