CVE-2001-0807 in Internet Explorer
Summary
by MITRE
Internet Explorer 5.0, and possibly other versions, may allow remote attackers (malicious web pages) to read known text files from a client s hard drive via a SCRIPT tag with a SRC value that points to the text file.
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Analysis
by VulDB Data Team • 04/07/2017
This vulnerability represents a classic cross-site scripting flaw that emerged in the early 2000s when internet explorer 5.0 was widely deployed. The security issue stems from how the browser handled script execution and file access permissions when processing external script sources through the script tag mechanism. Attackers could exploit this weakness by crafting malicious web pages that referenced local text files on the victim's system, effectively bypassing normal file access restrictions that should have prevented such operations.
The technical exploitation occurs through the SRC attribute of the script tag element which allows referencing external resources. When internet explorer 5.0 processed these references, it failed to properly validate or restrict access to local files, enabling attackers to specify paths to sensitive text files on the client machine. This flaw essentially allowed arbitrary file reading capabilities through web-based attacks, making it a significant concern for users who might encounter malicious web content. The vulnerability operates at the application layer and specifically targets the browser's security model for handling local file references.
The operational impact of this vulnerability extends beyond simple information disclosure. Attackers could potentially access configuration files, log files, or other sensitive text-based data stored locally on the victim's system. This capability represents a serious privacy and security threat as it enables unauthorized data collection without the user's knowledge or consent. The vulnerability was particularly dangerous because it required no special privileges or complex exploitation techniques, making it accessible to even less sophisticated attackers. This type of flaw aligns with CWE-22 which describes improper limitation of a pathname to a restricted directory, commonly known as path traversal attacks, and represents a precursor to more sophisticated local file inclusion vulnerabilities.
Organizations and users affected by this vulnerability should have implemented immediate mitigations including updating to patched versions of internet explorer, disabling script execution for untrusted content, and implementing network-based security controls such as web application firewalls. The vulnerability also highlighted the importance of proper input validation and the need for web browsers to maintain strict separation between local and remote resource access. From an att&ck perspective, this vulnerability maps to technique t1190 for exploitation through web applications and t1074 for data staging through local file access. Security professionals should have established monitoring for suspicious script tag usage patterns and implemented content security policies to prevent such cross-site scripting attacks. The incident underscored the critical need for browser vendors to implement robust security models that properly isolate local file system access from web content execution environments.