CVE-2005-1817 in IP.Board
Summary
by MITRE
Invision Power Board (IPB) 1.0 through 1.3 allows remote attackers to edit arbitrary forum posts via a direct request to index.php with modified parameters.
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Analysis
by VulDB Data Team • 07/28/2025
The vulnerability identified as CVE-2005-1817 affects Invision Power Board versions 1.0 through 1.3, representing a critical authorization flaw that enables remote attackers to manipulate forum content without proper authentication. This issue stems from insufficient input validation and access control mechanisms within the application's core functionality. The vulnerability specifically targets the index.php script which processes forum operations, allowing malicious actors to construct crafted HTTP requests that bypass normal permission checks. The flaw operates by manipulating URL parameters that control post editing functionality, effectively granting unauthorized users the ability to modify content across the entire forum system. This represents a fundamental breakdown in the application's security model where the lack of proper session validation and privilege verification creates an exploitable path for arbitrary code execution through content manipulation. The vulnerability directly maps to CWE-285, which addresses improper authorization issues, and aligns with ATT&CK technique T1078.101 for valid accounts usage, as attackers can leverage the bypass to perform actions they would not normally be permitted to execute.
The technical implementation of this vulnerability exploits the absence of proper access control validation when processing requests to the index.php endpoint. When users submit requests to modify forum posts, the application fails to verify whether the requesting user possesses the necessary permissions to perform such actions. Attackers can construct malicious URLs with modified parameters that point to the edit functionality, allowing them to modify any existing forum post regardless of their actual privileges. This flaw exists because the application relies on client-side parameter manipulation rather than server-side validation of user permissions and session integrity. The vulnerability demonstrates a classic case of insufficient input sanitization where the application trusts user-provided data without proper verification of the requesting user's authorization level. The exploitation process requires minimal technical expertise as it involves simple parameter modification, making it particularly dangerous for widely deployed forum platforms where administrators may not immediately detect unauthorized modifications to content.
The operational impact of this vulnerability extends beyond simple content tampering to potentially compromise the entire forum's integrity and user trust. Attackers can modify posts to include malicious links, deface the forum with inappropriate content, or alter discussions to misrepresent information shared by legitimate users. This vulnerability undermines the fundamental trust users place in forum platforms, as unauthorized modifications can occur without detection by forum administrators. The ability to edit arbitrary posts also creates potential for social engineering attacks where malicious actors can insert false information into discussions, potentially leading to misinformation campaigns or phishing attempts. Additionally, the vulnerability may enable attackers to escalate their privileges further by modifying administrator posts or creating malicious content that could compromise other users. The long-term consequences include reputational damage to forum administrators and potential legal implications if the compromised content violates regulations or contains harmful material. Organizations using affected versions of IPB face significant risk of content manipulation that could undermine their online community platforms and user engagement.
Mitigation strategies for CVE-2005-1817 require immediate implementation of proper access control mechanisms and input validation procedures. The primary solution involves implementing robust server-side validation that verifies user authentication and authorization before processing any post modification requests. Administrators should upgrade to patched versions of Invision Power Board where the vulnerability has been addressed through proper access control implementation. The fix should include session validation checks that ensure the requesting user has appropriate permissions before allowing any content modification operations. Additionally, implementing proper parameter validation and input sanitization techniques can prevent attackers from manipulating URL parameters to gain unauthorized access. Organizations should also consider implementing web application firewalls that can detect and block suspicious parameter modifications targeting forum functionality. Regular security audits and penetration testing should be conducted to identify similar authorization flaws in other applications. The vulnerability highlights the critical importance of proper access control implementation and serves as a reminder that even simple applications require comprehensive security measures to prevent unauthorized modifications. Security monitoring should be enhanced to detect unusual content modification patterns that may indicate exploitation attempts. Organizations should also implement proper logging mechanisms to track all post modification activities and establish alerting procedures for unauthorized access attempts. This vulnerability demonstrates the necessity of following security best practices including principle of least privilege, defense in depth, and regular security updates to maintain robust protection against exploitation attempts.