CVE-2002-1636

Step 1: Payload Delivery: The attacker crafts a malicious URL containing a specially crafted payload within the cbuf parameter. This payload typically includes HTML or JavaScript code designed to exploit the vulnerability.

Step 2: Request Submission: The attacker sends the malicious URL to a victim, often through phishing, social engineering, or by embedding it on a compromised website.

Step 3: Server Processing: The victim's browser sends the request to the Oracle 9iAS server.

Step 4: Vulnerable Function Execution: The server processes the request and calls the htp.print function with the attacker-controlled cbuf parameter.

Step 5: Unsanitized Output: The htp.print function, due to the lack of proper sanitization, directly includes the attacker's payload in the HTML response.

Step 6: Browser Execution: The victim's browser receives the response and, upon parsing the HTML, executes the injected JavaScript code. This code can then perform various malicious actions, such as stealing cookies, redirecting the user, or defacing the website.

The vulnerability lies within the htp.print function of the htp PL/SQL package in Oracle 9iAS. This function is responsible for printing content to the web page. The flaw occurs because the function fails to properly sanitize the cbuf parameter, which is used to pass the content to be printed. Specifically, the function does not adequately filter or encode HTML or JavaScript code embedded within the cbuf parameter. This allows an attacker to inject arbitrary HTML or JavaScript code into the output, which is then executed by the victim's browser. The root cause is a lack of input validation and output encoding (e.g., HTML entity encoding) of the cbuf parameter within the htp.print function. This allows malicious code to be interpreted by the browser.