CVE-2009-2441 in Online Guestbook Pro
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in ogp_show.php in Online Guestbook Pro 5.1 allows remote attackers to inject arbitrary web script or HTML via the entry parameter.
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Analysis
by VulDB Data Team • 07/27/2025
The vulnerability identified as CVE-2009-2441 represents a classic cross-site scripting flaw within the Online Guestbook Pro 5.1 web application. This issue resides in the ogp_show.php script which processes user input through the entry parameter, creating an avenue for malicious actors to execute arbitrary web scripts or HTML code within the context of other users' browsers. The vulnerability classification aligns with CWE-79 which specifically addresses Cross-Site Scripting conditions where untrusted data is improperly incorporated into web pages without proper validation or sanitization. This particular weakness enables attackers to bypass standard security measures that protect against malicious code execution in web environments.
The technical exploitation of this vulnerability occurs when a remote attacker crafts malicious input containing script code within the entry parameter of the guestbook submission process. When this malformed data is processed by the vulnerable ogp_show.php script, the application fails to properly sanitize or escape the user-supplied content before rendering it in the web page output. This allows the injected malicious code to execute within the browser context of legitimate users who view the affected guestbook entries. The flaw demonstrates a failure in input validation and output encoding practices that are fundamental to preventing XSS attacks in web applications.
The operational impact of this vulnerability extends beyond simple script injection, as it can enable attackers to perform various malicious activities including session hijacking, credential theft, and redirection to malicious websites. An attacker could craft entries that steal cookies from authenticated users, redirect them to phishing sites, or even modify the guestbook interface to display misleading information. The vulnerability affects the confidentiality, integrity, and availability of the web application by potentially compromising user sessions and undermining the trust users place in the guestbook functionality. This type of attack falls under the ATT&CK technique T1531 which involves the use of malicious code to gain access to user sessions and credentials.
Mitigation strategies for this vulnerability should focus on implementing robust input validation and output encoding mechanisms throughout the application. The most effective approach involves sanitizing all user inputs before processing and ensuring proper HTML escaping when rendering content back to users. Implementing Content Security Policy headers can provide additional protection layers against script execution. Organizations should also consider applying the principle of least privilege in web application design and regularly updating vulnerable software components. The vulnerability highlights the critical importance of input validation and output encoding practices that align with OWASP Top Ten security recommendations for preventing XSS attacks. Regular security assessments and code reviews should be conducted to identify and remediate similar vulnerabilities in web applications.