CVE-2018-0535 in PHP 2chBBS
Summary
by MITRE
Cross-site scripting vulnerability in PHP 2chBBS version bbs18c allows an attacker to inject arbitrary web script or HTML via unspecified vectors.
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Analysis
by VulDB Data Team • 01/15/2020
The CVE-2018-0535 vulnerability represents a critical cross-site scripting flaw within the PHP 2chBBS version bbs18c software ecosystem. This vulnerability stems from inadequate input validation and output sanitization mechanisms within the bulletin board system's codebase, creating an exploitable condition where malicious actors can inject arbitrary web scripts or HTML content into the application's response. The vulnerability affects the core functionality of the 2chBBS platform, which is a popular bulletin board system used for online forums and discussion platforms, making it a significant concern for organizations relying on this software for collaborative communication.
The technical exploitation of this vulnerability occurs through unspecified vectors that likely involve user input fields within the bulletin board interface. These vectors could include message posting areas, user profile fields, or any other input mechanisms where user-supplied data is processed and subsequently displayed without proper sanitization. The vulnerability maps to CWE-79 which specifically addresses Cross-Site Scripting flaws, where the application fails to properly validate or escape user-controllable data before incorporating it into dynamically generated web pages. This weakness allows attackers to execute malicious scripts in the context of other users' browsers, potentially leading to session hijacking, credential theft, or unauthorized actions performed on behalf of victims.
The operational impact of CVE-2018-0535 extends beyond simple script injection, as it can enable sophisticated attack vectors including session manipulation and data exfiltration. When exploited successfully, this vulnerability allows attackers to execute arbitrary JavaScript code within the victim's browser context, potentially compromising user sessions through cookie theft or redirecting users to malicious websites. The attack surface is particularly concerning given that 2chBBS is often deployed in environments where users share sensitive information or engage in collaborative work, making the potential for unauthorized access and data compromise significant. Organizations using this software face risks of reputational damage, regulatory compliance violations, and potential legal consequences if user data is compromised through such attacks.
Mitigation strategies for CVE-2018-0535 should focus on implementing comprehensive input validation and output encoding mechanisms throughout the application's codebase. The most effective approach involves applying proper HTML escaping to all user-controllable data before rendering it in web pages, ensuring that any potentially malicious script content is neutralized through encoding. Organizations should also implement Content Security Policy headers to limit the execution of unauthorized scripts and establish strict input validation routines that reject or sanitize any input containing potentially dangerous characters or patterns. Additionally, regular security updates and patches should be applied immediately upon availability, as the vulnerability affects a specific version of the software that likely contains known remediation paths. The remediation efforts should align with ATT&CK framework techniques related to defensive measures against web application attacks, particularly focusing on input validation and output encoding as primary defensive controls. Organizations must also conduct thorough code reviews and security assessments of their deployed systems to identify and remediate similar vulnerabilities that may exist in other components of their software infrastructure.