CVE-2000-0209 in Lynx
Summary
by MITRE
Buffer overflow in Lynx 2.x allows remote attackers to crash Lynx and possibly execute commands via a long URL in a malicious web page.
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Analysis
by VulDB Data Team • 04/20/2026
The vulnerability identified as CVE-2000-0209 represents a critical buffer overflow flaw within Lynx version 2.x web browsers that exposes remote attackers to potential system compromise. This vulnerability specifically manifests when the browser encounters a malformed URL exceeding its allocated buffer space during processing, creating a condition where malicious actors can manipulate the application's memory management and potentially gain unauthorized access to the underlying system. The issue stems from inadequate input validation mechanisms within the URL parsing component of the Lynx browser implementation.
This buffer overflow vulnerability operates through a classic exploitation vector where an attacker crafts a malicious web page containing an excessively long URL that surpasses the predetermined buffer limits within the Lynx application. When the browser attempts to process this malformed input, the overflow corrupts adjacent memory regions, potentially allowing attackers to overwrite critical program execution pointers and control the instruction flow of the application. The vulnerability falls under the CWE-121 category of buffer overflow conditions, specifically representing a stack-based buffer overflow that can be leveraged for arbitrary code execution when successfully exploited.
The operational impact of CVE-2000-0209 extends beyond simple application crashes to encompass potential system compromise and unauthorized access to sensitive information. When exploited successfully, this vulnerability enables remote attackers to execute arbitrary commands on the target system with the privileges of the Lynx process, which typically runs with user-level permissions but could potentially be escalated through additional exploitation techniques. The attack surface is particularly concerning given that Lynx was widely used as a text-based web browser in environments where command execution capabilities could be leveraged for further system infiltration or data exfiltration.
From a threat modeling perspective, this vulnerability aligns with ATT&CK technique T1059.007 for command and script interpreter execution, as successful exploitation would allow attackers to execute commands on the compromised system. The vulnerability also maps to T1190 for exploitation of remote services, as it enables remote code execution through web page content without requiring local system access. Mitigation strategies should prioritize immediate patching of affected Lynx versions, implementation of input validation controls, and network-level restrictions to prevent access to untrusted web content that could contain malicious URLs. Additionally, system administrators should consider deploying intrusion detection systems capable of identifying suspicious URL patterns and implementing application whitelisting policies to prevent execution of untrusted browser components. The vulnerability demonstrates the critical importance of proper buffer management and input validation in preventing remote code execution attacks, serving as a foundational example of why secure coding practices must be rigorously applied to all software components handling external input data.