CVE-2002-1348 in w3m
Summary
by MITRE
w3m before 0.3.2.2 does not properly escape HTML tags in the ALT attribute of an IMG tag, which could allow remote attackers to access files or cookies.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 07/19/2019
The vulnerability identified as CVE-2002-1348 affects the w3m web browser, a text-based web browser commonly used in terminal environments and embedded systems. This issue exists in versions prior to 0.3.2.2 and represents a classic cross-site scripting vulnerability that arises from improper handling of HTML content. The flaw specifically manifests when processing the ALT attribute within IMG tags, where the software fails to adequately sanitize or escape HTML markup characters that could be interpreted by the browser as actual HTML commands rather than simple text content.
The technical implementation of this vulnerability stems from insufficient input validation and output encoding mechanisms within the w3m rendering engine. When a web page containing an IMG tag with an ALT attribute is processed, the browser does not properly escape special HTML characters such as angle brackets, quotes, or other markup delimiters that might be present in the attribute value. This inadequate sanitization allows malicious actors to craft HTML content that, when rendered by the vulnerable w3m client, could execute unintended commands or reveal sensitive information to unauthorized parties.
The operational impact of this vulnerability extends beyond simple information disclosure, as it creates potential attack vectors for remote code execution and data theft. Attackers can exploit this weakness to access local files that the browser process has permission to read, potentially including system configuration files, user data, or sensitive cookies that store authentication tokens. The vulnerability particularly affects environments where w3m is used in conjunction with web applications that do not properly validate user input, creating a pathway for attackers to escalate privileges or gain unauthorized access to systems that rely on this browser for web content consumption.
This vulnerability aligns with CWE-79, which describes Cross-Site Scripting (XSS) flaws in web applications and browsers, and can be mapped to ATT&CK technique T1059.007 for command and scripting interpreter usage through web browser interfaces. The attack surface is particularly concerning in environments where w3m is used for automated web scraping, system administration tasks, or as a component in larger security tools that depend on proper HTML parsing and rendering. Organizations utilizing this browser for any security-sensitive operations should consider the implications of this vulnerability, as it could be leveraged to bypass security controls that assume proper HTML sanitization occurs during content rendering.
The remediation strategy for CVE-2002-1348 involves upgrading to w3m version 0.3.2.2 or later, which includes proper HTML escape sequence handling in the ALT attribute processing. Additionally, system administrators should implement input validation measures at the network level to filter potentially malicious HTML content before it reaches vulnerable clients, and consider deploying web application firewalls that can detect and block suspicious HTML constructs. Regular security audits of embedded systems and terminal-based applications that utilize w3m should include checks for this specific vulnerability to ensure proper patch management and maintain security posture against known exploitation techniques.