CVE-2002-1645 in SSH
Summary
by MITRE
Buffer overflow in the URL catcher feature for SSH Secure Shell for Workstations client 3.1 to 3.2.0 allows remote attackers to execute arbitrary code via a long URL.
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Analysis
by VulDB Data Team • 11/18/2024
The vulnerability identified as CVE-2002-1645 represents a critical buffer overflow flaw within the SSH Secure Shell for Workstations client version 3.1 through 3.2.0. This issue specifically affects the URL catcher functionality, which is designed to handle and process uniform resource locator information within the secure shell environment. The buffer overflow occurs when the client processes excessively long URL strings, creating a condition where memory boundaries are exceeded and potentially allowing malicious code execution. This vulnerability falls under the CWE-121 buffer overflow category, which is classified as a fundamental memory safety issue that has been consistently exploited in numerous security incidents over the years. The flaw demonstrates a classic stack-based buffer overflow where insufficient input validation permits attackers to overwrite adjacent memory locations, potentially leading to arbitrary code execution with the privileges of the affected process.
The technical exploitation of this vulnerability requires a remote attacker to craft a maliciously long URL string that exceeds the allocated buffer space within the SSH client application. When the client attempts to process this oversized URL through its URL catcher feature, the overflow corrupts the stack memory, potentially allowing an attacker to overwrite return addresses and function pointers. This type of exploitation aligns with the attack pattern described in the MITRE ATT&CK framework under the technique T1059.007 for command and scripting interpreter, where attackers leverage buffer overflows to execute malicious code. The vulnerability affects the client-side component of the SSH Secure Shell implementation, making it particularly dangerous as users may unknowingly trigger the exploit when clicking on malicious links or when the client automatically processes URLs from network sources.
The operational impact of CVE-2002-1645 extends beyond simple code execution, as it can enable complete system compromise when exploited successfully. An attacker who successfully exploits this vulnerability can gain arbitrary code execution capabilities within the context of the SSH client process, potentially leading to privilege escalation, data theft, or further network infiltration. The vulnerability is particularly concerning because it affects a widely used SSH client implementation, meaning that successful exploitation could compromise numerous systems across different organizations. The attack surface is expanded by the fact that the URL catcher feature may be triggered automatically during normal client operations, reducing the need for direct user interaction. This characteristic makes the vulnerability more dangerous as it could be exploited through passive means without requiring specific user actions beyond normal SSH client usage patterns.
Mitigation strategies for CVE-2002-1645 should prioritize immediate patching of affected SSH Secure Shell for Workstations versions, as the vendor has released updates addressing this specific buffer overflow vulnerability. Organizations should implement network segmentation to limit exposure to potentially malicious URLs and consider disabling the URL catcher feature entirely if it is not essential for business operations. The implementation of input validation controls and bounds checking within the SSH client application would provide additional defense-in-depth measures, aligning with security best practices outlined in the OWASP Top Ten and NIST cybersecurity guidelines. Regular security assessments and vulnerability scanning should be conducted to identify any unpatched systems, while network monitoring can help detect potential exploitation attempts through unusual URL processing patterns. Additionally, user education regarding the risks of clicking on untrusted links and the importance of keeping security software updated remains crucial in preventing successful exploitation of this and similar vulnerabilities.