CVE-2001-1323 in Kerberos
Summary
by MITRE
Buffer overflow in MIT Kerberos 5 (krb5) 1.2.2 and earlier allows remote attackers to cause a denial of service and possibly execute arbitrary code via base-64 encoded data, which is not properly handled when the radix_encode function processes file glob output from the ftpglob function.
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Analysis
by VulDB Data Team • 05/30/2018
The vulnerability identified as CVE-2001-1323 represents a critical buffer overflow flaw within MIT Kerberos 5 version 1.2.2 and earlier implementations. This security weakness specifically manifests in the krb5 software suite's handling of base-64 encoded data during the processing of file glob output from the ftpglob function. The flaw exists in the radix_encode function which fails to properly validate or limit the size of input data, creating an exploitable condition that can be leveraged by remote attackers to compromise system integrity.
The technical implementation of this vulnerability stems from inadequate input validation mechanisms within the Kerberos authentication system. When the ftpglob function processes file glob patterns and subsequently passes this data to radix_encode for base-64 encoding, the system does not enforce proper bounds checking on the resulting output buffer. This allows attackers to craft malicious base-64 encoded input that exceeds the allocated buffer space, leading to memory corruption and potential arbitrary code execution. The vulnerability operates at the intersection of network-based attack vectors and local privilege escalation scenarios, making it particularly dangerous in networked environments where Kerberos services are deployed.
From an operational impact perspective, this vulnerability creates significant risks for organizations relying on MIT Kerberos for authentication services. Remote attackers can exploit this flaw to cause denial of service conditions that disrupt authentication services, potentially rendering critical systems inaccessible to legitimate users. More critically, the buffer overflow condition may enable attackers to execute arbitrary code with the privileges of the affected service, potentially leading to complete system compromise. The vulnerability affects systems where Kerberos is used for authentication, including but not limited to network file systems, email servers, and enterprise authentication infrastructures that depend on the krb5 implementation.
Security professionals should implement immediate mitigations including upgrading to MIT Kerberos 5 version 1.2.3 or later, which contains patches addressing the buffer overflow condition in the radix_encode function. Organizations should also consider implementing network segmentation and access controls to limit exposure of Kerberos services to untrusted networks. The vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and represents a classic example of improper input validation that enables code execution. From an ATT&CK framework perspective, this vulnerability maps to techniques involving remote code execution and privilege escalation, specifically targeting the credential access and execution phases of the attack lifecycle. System administrators should also conduct thorough vulnerability assessments to identify any systems running vulnerable versions of the krb5 software and ensure proper patch management procedures are in place to prevent exploitation of this and similar buffer overflow vulnerabilities.