CVE-2002-0600 in Kerberos
Summary
by MITRE
Heap overflow in the KTH Kerberos 4 FTP client 4-1.1.1 allows remote malicious servers to execute arbitrary code on the client via a long response to a passive (PASV) mode request.
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Analysis
by VulDB Data Team • 06/22/2024
The vulnerability identified as CVE-2002-0600 represents a critical heap overflow flaw in the KTH Kerberos 4 FTP client version 4-1.1.1 that fundamentally compromises client security through a specific network interaction pattern. This vulnerability operates within the context of the File Transfer Protocol where clients establish connections with servers using passive mode requests, creating a communication channel that malicious actors can exploit to gain unauthorized code execution capabilities.
The technical flaw manifests as a heap buffer overflow occurring when the KTH Kerberos 4 FTP client processes a maliciously crafted response from a remote FTP server during passive mode (PASV) operations. When the client receives a long response to a PASV command, the application fails to properly validate the response length before copying it into a fixed-size heap buffer, causing data to overflow into adjacent memory regions. This memory corruption directly enables attackers to overwrite critical memory locations including return addresses and function pointers, thereby allowing arbitrary code execution with the privileges of the affected client process.
The operational impact of this vulnerability extends beyond simple remote code execution to encompass complete system compromise when exploited successfully. An attacker positioned between the client and server or controlling a malicious FTP server can craft a response that triggers the heap overflow, potentially leading to privilege escalation, data theft, system takeover, or further network infiltration. The vulnerability is particularly dangerous because it requires no authentication from the attacker, as the malicious response can be sent by any FTP server that the client connects to, making it a significant risk for any system using this vulnerable FTP client implementation.
This vulnerability aligns with CWE-121, heap-based buffer overflow, and represents a classic example of improper input validation in network protocols. From an ATT&CK framework perspective, this vulnerability maps to T1059.007 (Command and Scripting Interpreter: PowerShell) and T1068 (Exploitation for Privilege Escalation) as it enables initial compromise through network-based exploitation followed by privilege escalation. The attack chain typically begins with network access to the vulnerable client, followed by crafting of malicious FTP responses, and concludes with remote code execution. Organizations should implement immediate mitigations including upgrading to patched versions of the KTH Kerberos 4 FTP client, implementing network segmentation to prevent access to untrusted FTP servers, and applying firewall rules that restrict FTP traffic to trusted endpoints. The vulnerability also underscores the importance of proper memory management practices and input validation in network protocol implementations, particularly in security-critical applications that handle remote data processing.