Source: cve@mitre.org
Cross-site scripting (XSS) vulnerability in the View URL Database functionality in Sun Java System Web Proxy Server 4.x before 4.0.6 and 3.x before 3.6 SP11 allows remote attackers to inject arbitrary web script or HTML via unspecified vectors, aka BugID 6566309.
Sun Java System Web Proxy Server versions 4.x (before 4.0.6) and 3.x (before 3.6 SP11) are vulnerable to a cross-site scripting (XSS) attack. This allows attackers to inject malicious scripts into the proxy server's web interface, potentially leading to session hijacking, data theft, and complete compromise of the server and its users.
Step 1: Payload Delivery: The attacker crafts a malicious URL or a specially formatted request that, when processed by the vulnerable proxy server, injects JavaScript code into the 'View URL Database' functionality. This could involve manipulating parameters passed to the server or crafting a malicious entry in the URL database. Step 2: Data Storage: The malicious input, containing the JavaScript payload, is stored within the URL database or processed by the server in a way that allows it to persist. Step 3: Victim Interaction: A user with access to the proxy server's web interface, such as an administrator or a user viewing the URL database, accesses the vulnerable page. Step 4: Payload Execution: The proxy server retrieves the malicious data from the database and renders it in the HTML response without proper sanitization. The victim's browser then executes the injected JavaScript code.
The vulnerability stems from insufficient input validation and output encoding within the 'View URL Database' functionality. Specifically, the application fails to properly sanitize user-supplied input before rendering it in the web interface. This allows attackers to inject malicious JavaScript code into the HTML response, which is then executed by the victim's browser. The root cause is a lack of proper input validation and output encoding (e.g., HTML entity encoding) of user-controlled data when displaying entries from the URL database. The application trusts the input, leading to the execution of arbitrary code.
While no specific APT groups are directly linked to this CVE, the nature of XSS vulnerabilities makes them attractive to a wide range of attackers, including those seeking to steal credentials, redirect users to malicious websites, or gain control of the server. This vulnerability could be used as part of a larger attack chain. This CVE is not listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, but the age and nature of the vulnerability suggest that it could be leveraged in conjunction with other vulnerabilities.
Monitor web server logs for suspicious HTTP requests, particularly those containing JavaScript code or HTML tags in URL parameters or POST data.
Analyze network traffic for unusual patterns, such as unexpected JavaScript execution or redirects.
Implement a Web Application Firewall (WAF) to detect and block XSS attacks.
Review the server's configuration and access logs for unauthorized changes or suspicious activity related to the URL database.
Use a vulnerability scanner to identify the presence of this and other vulnerabilities.
Upgrade to Sun Java System Web Proxy Server 4.0.6 or later, or 3.6 SP11 or later.
Implement a Web Application Firewall (WAF) to filter malicious input.
Apply input validation and output encoding to all user-supplied data to prevent XSS attacks. Specifically, ensure that all data displayed in the web interface is properly HTML-encoded.
Regularly scan the server for vulnerabilities.
Review and harden the server's configuration, including disabling unnecessary features and services.
Implement the principle of least privilege for user accounts.