CVE-2000-1205 in HTTP Server
Summary
by MITRE
Cross site scripting vulnerabilities in Apache 1.3.0 through 1.3.11 allow remote attackers to execute script as other web site visitors via (1) the printenv CGI (printenv.pl), which does not encode its output, (2) pages generated by the ap_send_error_response function such as a default 404, which does not add an explicit charset, or (3) various messages that are generated by certain Apache modules or core code. NOTE: the printenv issue might still exist for web browsers that can render text/plain content types as HTML, such as Internet Explorer, but CVE regards this as a design limitation of those browsers, not Apache. The printenv.pl/acuparam vector, discloser on 20070724, is one such variant.
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Analysis
by VulDB Data Team • 04/20/2026
The vulnerability described in CVE-2000-1205 represents a critical cross site scripting flaw affecting Apache web servers version 1.3.0 through 1.3.11, with implications for web application security and user data integrity. This vulnerability stems from inadequate output encoding and improper content type handling within the Apache HTTP server implementation, creating opportunities for malicious actors to inject and execute arbitrary script code within the context of other users' browsers. The flaw manifests across multiple attack vectors, demonstrating the widespread nature of the encoding deficiency in the server's response handling mechanisms.
The primary attack vectors identified in this vulnerability encompass three distinct areas of Apache's functionality where output encoding fails to properly sanitize data before transmission to web browsers. The first vector involves the printenv CGI script printenv.pl which fails to encode its output, allowing attackers to inject malicious scripts that execute when other users view the script's output. The second vector targets pages generated by the ap_send_error_response function, particularly default 404 error pages that lack explicit charset declarations, creating opportunities for script injection in error responses. The third vector involves various messages generated by specific Apache modules or core code components, where the server fails to properly encode potentially malicious content before delivery. These multiple attack surfaces highlight the fundamental nature of the encoding problem within the Apache server architecture.
The operational impact of this vulnerability extends beyond simple script execution to potentially compromise user sessions, steal sensitive information, and manipulate web application behavior. When attackers exploit these vectors, they can redirect users to malicious sites, steal cookies and session data, or modify page content in ways that deceive users into believing they are interacting with legitimate web services. The vulnerability's persistence across different Apache versions demonstrates that the underlying encoding flaw was not properly addressed in the server's core response handling mechanisms, creating a long-term security risk for organizations running affected Apache installations. The fact that the printenv issue remains relevant for certain browsers like Internet Explorer, despite being classified as a browser design limitation, underscores the complexity of web security and the need for comprehensive server-side protection measures.
Organizations affected by this vulnerability should implement immediate mitigations including updating to Apache versions beyond 1.3.11 where the encoding issues have been addressed, implementing proper output encoding for all CGI scripts and error responses, and configuring explicit charset declarations in HTTP headers. The vulnerability aligns with CWE-79 Cross Site Scripting and follows patterns commonly associated with ATT&CK technique T1059.007 Command and Scripting Interpreter: JavaScript, demonstrating how server-side flaws can enable client-side attack vectors. Security practitioners should also consider implementing web application firewalls, content security policies, and regular security assessments to prevent similar encoding vulnerabilities from emerging in other web server components or custom applications that may be vulnerable to similar injection attacks.