CVE-2005-0818 in PunBB
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in PunBB 1.2.3 allows remote attackers to inject arbitrary web script or HTML via the (1) email or (2) Jabber parameters.
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Analysis
by VulDB Data Team • 10/30/2025
The CVE-2005-0818 vulnerability represents a critical cross-site scripting flaw discovered in PunBB version 1.2.3, a popular open-source bulletin board system. This vulnerability exposes the application to remote code execution risks when attackers exploit improperly validated user input fields. The flaw specifically affects two parameter fields within the application's user registration or profile update functionality, namely the email and Jabber parameters, which are commonly used for user communication settings. The vulnerability stems from inadequate input sanitization mechanisms that fail to properly escape or validate user-supplied data before rendering it within web pages.
The technical implementation of this XSS vulnerability occurs when the PunBB application processes user-provided email or Jabber address information without sufficient validation or output encoding. When an attacker submits malicious script code within either of these fields, the application stores the input without proper sanitization and subsequently renders it in web responses without appropriate HTML escaping. This creates an environment where the malicious script executes within the context of other users' browsers who view the affected profile information, potentially leading to session hijacking, credential theft, or redirection to malicious websites. The vulnerability operates under CWE-79 which specifically addresses Cross-Site Scripting flaws in web applications.
The operational impact of this vulnerability extends beyond simple data corruption or display issues, as it enables attackers to compromise user sessions and potentially gain unauthorized access to sensitive information. An attacker could craft malicious payloads that exploit the vulnerability by injecting JavaScript code that steals cookies, redirects users to phishing sites, or performs actions on behalf of authenticated users. The attack vector is particularly concerning because it requires minimal privileges to exploit, as the vulnerability exists within legitimate user input fields that are expected to contain valid email addresses or Jabber identifiers. This makes the vulnerability difficult to detect and can persist for extended periods if not properly addressed.
Security practitioners should implement immediate mitigations including input validation and output encoding for all user-supplied data, particularly in fields that are rendered in web contexts. The recommended approach involves implementing strict input validation that rejects or sanitizes potentially malicious content before processing, combined with proper HTML escaping when displaying user-generated content. Organizations should also consider implementing Content Security Policy headers to limit script execution capabilities and utilize web application firewalls to detect and block malicious payloads. This vulnerability aligns with ATT&CK technique T1059.007 for Scripting and T1566.001 for Phishing, demonstrating how XSS flaws can enable more sophisticated attack chains. The vulnerability underscores the importance of following secure coding practices and implementing comprehensive input validation mechanisms as outlined in OWASP Top Ten and NIST cybersecurity guidelines, particularly focusing on preventing injection attacks and ensuring proper data sanitization throughout application development lifecycle processes.