Source: cve@mitre.org
Cross-site scripting (XSS) vulnerability in Sun Java System Web Server 6.1 before SP8 and 7.0 before Update 1 allows remote attackers to inject arbitrary web script or HTML via unspecified vectors, aka BugID 6566204.
Sun Java System Web Server versions 6.1 (before SP8) and 7.0 (before Update 1) are vulnerable to a cross-site scripting (XSS) attack. This allows attackers to inject malicious scripts into web pages viewed by other users, potentially leading to account compromise or data theft.
Step 1: Payload Delivery: The attacker crafts a malicious URL containing a JavaScript payload within a parameter or input field that the web server processes and displays.
Step 2: Request Submission: The attacker sends the crafted URL to a victim, typically through phishing, social engineering, or by embedding it in a compromised website.
Step 3: Server Processing: The vulnerable web server receives the malicious request and processes it, including the attacker-supplied payload.
Step 4: Response Generation: The server, failing to properly sanitize the input, includes the attacker's JavaScript payload in the HTML response it sends back to the victim's browser.
Step 5: Browser Execution: The victim's browser receives the malicious HTML response and executes the embedded JavaScript code, as it trusts the web server's origin. This allows the attacker's script to run within the context of the web server's domain.
Step 6: Exploitation: The attacker's JavaScript code can then perform various malicious actions, such as stealing cookies, redirecting the user to a phishing site, or modifying the content of the web page.
The vulnerability stems from insufficient input validation and output encoding within the Sun Java System Web Server. Specifically, the server fails to properly sanitize user-supplied data before rendering it in the HTML response. This allows attackers to inject malicious JavaScript code, which is then executed by the victim's browser. The root cause is likely a missing or inadequate implementation of input validation and output encoding functions, such as escaping special characters like < and > or using a secure context for dynamic content. The lack of proper sanitization allows the attacker to craft a payload that bypasses security checks and executes arbitrary code in the context of the vulnerable web server.
While no specific APT groups are directly linked to this CVE, XSS vulnerabilities are commonly used by various threat actors. This vulnerability could be used as a stepping stone to further attacks. CISA KEV status: Not Listed
Monitor web server logs for suspicious HTTP requests containing JavaScript payloads (e.g., <script>, onerror, javascript:).
Analyze HTTP response headers for evidence of XSS vulnerabilities (e.g., missing Content-Security-Policy (CSP) headers).
Implement a Web Application Firewall (WAF) to detect and block XSS attempts.
Use network intrusion detection systems (IDS) to identify malicious traffic patterns associated with XSS attacks.
Examine the source code of web pages for potentially vulnerable areas where user-supplied data is displayed without proper sanitization.
Upgrade to the latest version of Sun Java System Web Server or apply the relevant security patches (SP8 for 6.1, Update 1 for 7.0).
Implement robust input validation to sanitize all user-supplied data before processing it.
Implement output encoding to escape special characters (e.g., <, >, &, ", ') when displaying user-supplied data in HTML.
Implement Content Security Policy (CSP) to restrict the sources from which the browser can load resources, mitigating the impact of XSS attacks.
Use a Web Application Firewall (WAF) to filter malicious requests.
Regularly scan the web application for XSS vulnerabilities using automated tools and manual penetration testing.