CVE-2005-1969 in Pragma Telnetserver
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in Pragma Systems Telnetserver 6.0 allows remote attackers to inject arbitrary web script or HTML, and hide activities in log files, via a "<!--" (HTML comment) in a session.
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Analysis
by VulDB Data Team • 07/25/2017
The vulnerability identified as CVE-2005-1969 represents a critical cross-site scripting flaw within Pragma Systems Telnetserver 6.0 that enables remote attackers to execute malicious web scripts or HTML code. This security weakness specifically manifests through the improper handling of HTML comments in session data, allowing adversaries to inject malicious payloads that can compromise user sessions and manipulate web content. The vulnerability stems from inadequate input validation and sanitization mechanisms within the telnet server's session management system, where HTML comment delimiters are not properly escaped or filtered before being processed or displayed in web interfaces.
The technical exploitation of this vulnerability occurs when an attacker crafts a session request containing the "<!--" HTML comment sequence, which the vulnerable telnet server fails to properly sanitize. This allows the malicious code to be executed in the context of other users' browsers, potentially enabling session hijacking, data theft, or unauthorized actions. The attacker can leverage this weakness to hide their malicious activities within legitimate log files by embedding the HTML comment syntax, making detection more difficult while simultaneously executing harmful scripts. This particular implementation flaw demonstrates a failure in proper output encoding and input validation practices that are fundamental to preventing XSS attacks.
The operational impact of this vulnerability extends beyond simple script execution to include significant security implications for organizations relying on Pragma Systems Telnetserver 6.0 for remote access management. Attackers can exploit this weakness to impersonate legitimate users, access sensitive data, or manipulate session states, potentially leading to complete system compromise. The ability to hide malicious activities within log files creates a sophisticated attack vector that can evade traditional security monitoring systems. Additionally, the vulnerability affects the integrity of session management processes, potentially allowing attackers to maintain persistent access or escalate privileges within the affected environment. This weakness particularly impacts organizations that depend on telnet-based remote access solutions for administrative tasks.
Mitigation strategies for CVE-2005-1969 should focus on immediate patching of the vulnerable telnet server software, as well as implementing comprehensive input validation and output encoding mechanisms. Organizations should deploy web application firewalls that can detect and block malicious HTML comment sequences, while also establishing proper logging and monitoring procedures that can identify anomalous patterns in session data. The remediation process must include thorough code review of session handling components to ensure proper HTML entity encoding and input sanitization. Security controls should be implemented to prevent the injection of HTML comments and other potentially dangerous markup elements in user-supplied data. This vulnerability aligns with CWE-79 which specifically addresses cross-site scripting flaws, and represents a technique commonly referenced in ATT&CK framework under the T1059.007 sub-technique for script injection, emphasizing the importance of proper input validation in preventing such remote code execution scenarios.