The validate_as_request function in kdc_util.c in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) before 1.13.6 and 1.4.x before 1.14.3, when restrict_anonymous_to_tgt is enabled, uses an incorrect client data structure, which allows remote authenticated users to cause a denial of service (NULL pointer dereference and daemon crash) via an S4U2Self request.
This vulnerability carries a MEDIUM severity rating with a CVSS v3.1 score of 6.5, indicating it can be exploited remotely over the network with relatively low complexity without requiring user interaction requiring only low-level privileges . The vulnerability impacts and availability (service disruption) for affected systems. Impacting 1 product from mit organizations running these solutions should prioritize assessment and patching.
First disclosed in 2016, this vulnerability was reported during a period defined by widespread IoT adoption challenges, mobile security concerns, and the emergence of advanced persistent threat (APT) techniques. Contemporary mitigation strategies focused on secure development practices and third-party component vetting.
2016-08-01T02:59:12.370
2026-05-06T22:30:45.220
Modified
CVSSv3.0: 6.5 (MEDIUM)
AV:N/AC:L/Au:S/C:N/I:N/A:P
8.0
2.9
| Type | Vendor | Product | Version/Range | Vulnerable? |
|---|---|---|---|---|
| Application | mit | kerberos_5 | 1.13 | Yes |
| Application | mit | kerberos_5 | 1.13.1 | Yes |
| Application | mit | kerberos_5 | 1.13.2 | Yes |
| Application | mit | kerberos_5 | 1.13.3 | Yes |
| Application | mit | kerberos_5 | 1.13.4 | Yes |
| Application | mit | kerberos_5 | 1.13.5 | Yes |
| Application | mit | kerberos_5 | 1.13.6 | Yes |
| Application | mit | kerberos_5 | 1.14 | Yes |
| Application | mit | kerberos_5 | 1.14.1 | Yes |
| Application | mit | kerberos_5 | 1.14.2 | Yes |
SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For mit's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.