CVE-2002-2339 in Ssgbook
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in configure.asp in Script-Shed GuestBook 1.0 allows remote attackers to inject arbitrary web script or HTML via a javascript: URL in (1) image, (2) img, (3) image=right, (4) img=right, (5) image=left, and (6) img=left tags.
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Analysis
by VulDB Data Team • 08/28/2025
The vulnerability described in CVE-2002-2339 represents a classic cross-site scripting flaw within the Script-Shed GuestBook 1.0 web application. This security weakness exists in the configure.asp component which processes user input without proper sanitization or validation. The flaw specifically affects how the application handles image-related parameters in guestbook entries, creating an avenue for malicious actors to execute arbitrary scripts in the context of other users' browsers. The vulnerability manifests when users submit guestbook entries containing javascript: URLs within various image tag parameters, allowing attackers to inject malicious code that executes in the victim's browser environment.
The technical implementation of this vulnerability stems from insufficient input validation and output encoding practices within the guestbook application. When the configure.asp script processes the image parameters such as image, img, image=right, img=right, image=left, and img=left, it fails to properly sanitize user-supplied data before rendering it back to web browsers. This lack of proper input filtering creates a condition where javascript: URLs can be embedded within the image attributes, bypassing normal security restrictions. The vulnerability is classified under CWE-79 as a failure to sanitize user input, specifically manifesting as a reflected cross-site scripting vulnerability where malicious scripts are injected into web pages viewed by other users.
The operational impact of this vulnerability extends beyond simple data theft or defacement. Attackers can leverage this weakness to execute malicious scripts that may steal session cookies, redirect users to phishing sites, or perform unauthorized actions on behalf of victims. Since the vulnerability affects guestbook functionality, it typically requires minimal user interaction for exploitation, as users may unknowingly click on malicious links embedded within guestbook entries. The attack surface is particularly concerning in environments where guestbooks are publicly accessible and widely used, as the vulnerability can affect numerous users simultaneously. This type of vulnerability aligns with ATT&CK technique T1566.001 for initial access through spearphishing attachments and T1588.001 for development of capabilities involving web-based attacks.
Mitigation strategies for this vulnerability should focus on implementing comprehensive input validation and output encoding mechanisms. The most effective approach involves sanitizing all user-provided input before processing or rendering it within web pages, particularly for attributes that may contain URL parameters. Web applications should employ proper HTML encoding for any dynamic content that originates from user input, ensuring that special characters are properly escaped. Additionally, implementing a content security policy that restricts the execution of inline scripts and limits the sources from which scripts can be loaded would provide defense-in-depth. Organizations should also consider implementing web application firewalls that can detect and block suspicious patterns in URL parameters. The vulnerability highlights the critical importance of input validation and output encoding practices that should be integrated into all web application development processes, following security standards such as those outlined in OWASP Top 10 and the NIST Cybersecurity Framework for secure coding practices.