CVE-2007-4912 in IP.Board
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in ips_kernel/class_ajax.php in Invision Power Board (IPB or IP.Board) 2.3.1 up to 20070912 allows remote attackers to inject arbitrary web script or HTML into user profile fields via unspecified vectors related to character sets other than iso-8859-1 or utf-8.
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Analysis
by VulDB Data Team • 10/29/2017
The vulnerability CVE-2007-4912 represents a cross-site scripting flaw discovered in Invision Power Board version 2.3.1 and earlier releases, specifically within the ips_kernel/class_ajax.php component. This issue affects web applications that process user-generated content and demonstrates a critical weakness in input validation and output encoding mechanisms. The vulnerability manifests when the application handles character sets that differ from the standard iso-8859-1 or utf-8 encodings, creating a pathway for malicious actors to inject harmful scripts into user profile fields. The flaw operates at the application layer and specifically targets the handling of international character encodings, making it particularly dangerous in multilingual environments where various character sets are processed.
The technical exploitation of this vulnerability occurs through the manipulation of character encoding parameters within the AJAX processing functionality of the IPB platform. When user profiles contain data processed through the affected class_ajax.php file, the system fails to properly sanitize or encode input that uses character sets outside the standard iso-8859-1 and utf-8 ranges. This inadequate sanitization allows attackers to embed malicious JavaScript code or HTML content within profile fields, which then gets executed when other users view these profiles. The vulnerability stems from insufficient input validation and output encoding practices, creating a condition where user-supplied data can bypass security measures designed to prevent script injection attacks. This flaw directly aligns with CWE-79 which categorizes cross-site scripting vulnerabilities as weaknesses in input validation and output encoding.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable attackers to perform session hijacking, steal user credentials, redirect victims to malicious sites, or perform actions on behalf of users. When exploited successfully, the vulnerability allows remote attackers to inject persistent scripts that can compromise user sessions and potentially escalate privileges within the application. The attack vector is particularly concerning because it targets profile fields, which are typically considered safe user-generated content areas where users expect to see their own information. This makes the attack less suspicious to end users and increases the likelihood of successful exploitation. The vulnerability also impacts the integrity and confidentiality of user data, as malicious scripts can capture sensitive information or modify user profiles to propagate further attacks.
Mitigation strategies for CVE-2007-4912 should focus on implementing comprehensive input validation and output encoding mechanisms throughout the application. Organizations should ensure that all user-supplied data undergoes strict sanitization regardless of the character encoding used, with particular attention to character set handling in AJAX components. The recommended approach includes implementing proper HTML entity encoding for all output, utilizing whitelisting techniques for accepted character sets, and ensuring that the application consistently handles character encodings in a secure manner. Security patches should be applied immediately to update the affected IPB versions, and developers should implement proper content security policies to prevent script execution. Additionally, regular security assessments should verify that similar encoding-related vulnerabilities do not exist in other components of the application. This vulnerability demonstrates the importance of following secure coding practices and aligns with ATT&CK technique T1059.001 for command and script injection, emphasizing the need for robust input validation at all application layers.