CVE-2007-6460 in Anon Proxy Server
Summary
by MITRE
Multiple cross-site scripting (XSS) vulnerabilities in Anon Proxy Server before 0.101 allow remote attackers to inject arbitrary web script or HTML via the URI, which is later displayed by (1) log.php or (2) logerror.php, a different vulnerability than CVE-2007-6459.
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Analysis
by VulDB Data Team • 11/03/2017
The CVE-2007-6460 vulnerability represents a critical cross-site scripting flaw in the Anon Proxy Server software prior to version 0.101. This vulnerability exposes the system to remote code execution risks through malicious script injection in the URI parameter that gets processed and displayed by specific log handling scripts. The vulnerability specifically affects two distinct files within the application's logging infrastructure: log.php and logerror.php, which serve as the primary vectors for script injection attacks. These files process and display user-provided URI data without proper input validation or output encoding, creating an exploitable condition that allows attackers to inject malicious HTML or JavaScript code directly into the application's response.
The technical nature of this vulnerability aligns with CWE-79, which describes cross-site scripting flaws occurring when untrusted data is sent to a web browser without proper sanitization or encoding. The flaw exists in the application's data handling pipeline where user-supplied URI parameters are directly incorporated into the HTML output without adequate security controls. When an attacker crafts a malicious URI containing script code, the proxy server processes this input and subsequently displays it in the log.php or logerror.php scripts, thereby executing the injected code in the context of the victim's browser session. This represents a classic server-side XSS vulnerability where the application itself becomes the vector for delivering malicious content to unsuspecting users.
The operational impact of CVE-2007-6460 extends beyond simple script injection, as it provides attackers with the capability to perform session hijacking, deface the application interface, steal sensitive cookies, or redirect users to malicious sites. The vulnerability's persistence in the logging files means that the injected scripts can affect multiple users over time, as the log files remain accessible to authenticated users. Attackers could exploit this vulnerability to create persistent backdoors, harvest user credentials, or establish command and control channels through the proxy server's logging infrastructure. The fact that this vulnerability operates through the proxy server's logging mechanism also means that it could be leveraged to bypass certain network security controls that might not monitor or filter log file content.
Organizations using vulnerable versions of Anon Proxy Server should immediately implement mitigations including input validation and output encoding for all URI parameters before they are processed by the logging scripts. The recommended approach involves implementing strict sanitization of user input, particularly in URI components, and ensuring that all output generated by log.php and logerror.php is properly encoded to prevent script execution. Additionally, implementing proper access controls for log files and regular monitoring of log file contents can help detect potential exploitation attempts. Security professionals should consider deploying web application firewalls that can detect and block XSS patterns in URI parameters, while also ensuring that the proxy server is updated to version 0.101 or later where these vulnerabilities have been addressed. The vulnerability demonstrates the importance of input validation and output encoding in preventing XSS attacks and aligns with ATT&CK technique T1566, which covers the use of web applications as attack vectors for executing malicious code against users.