CVE-2006-2949 in MyBB
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in private.php in MyBB 1.1.2 allows remote attackers to inject arbitrary web script or HTML via the do parameter.
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Analysis
by VulDB Data Team • 04/30/2019
The vulnerability identified as CVE-2006-2949 represents a classic cross-site scripting flaw within the MyBB 1.1.2 forum software, specifically affecting the private.php script. This type of vulnerability falls under the CWE-79 category, which encompasses cross-site scripting attacks that occur when untrusted data is embedded into web pages viewed by other users. The vulnerability manifests in the handling of the do parameter, which is processed without adequate input validation or output sanitization, creating an exploitable entry point for malicious actors to inject arbitrary web scripts or HTML content.
The technical implementation of this vulnerability exploits the insecure processing of user-supplied input within the private messaging functionality of MyBB. When a user accesses the private.php script with a maliciously crafted do parameter, the application fails to properly sanitize or escape the input before rendering it within the web page context. This allows an attacker to inject JavaScript code or HTML elements that execute in the victim's browser when they view the affected page. The vulnerability is particularly dangerous because it operates at the application layer, targeting the web interface directly without requiring any special privileges or access to the underlying system.
The operational impact of this vulnerability extends beyond simple script injection, as it can enable attackers to perform various malicious activities including session hijacking, credential theft, defacement of forum content, and redirection to malicious sites. The attacker can leverage this vulnerability to steal session cookies from authenticated users, potentially gaining unauthorized access to their accounts and private messages. Additionally, the injection of malicious scripts could lead to data exfiltration, modification of forum content, or the creation of backdoors within the compromised system. The widespread use of MyBB 1.1.2 in 2006 meant that numerous forums were potentially exposed to this vulnerability, creating a significant attack surface for threat actors.
Mitigation strategies for this vulnerability should include immediate patching of the MyBB software to version 1.1.3 or later, which contained the necessary fixes for the XSS vulnerability. Organizations should also implement proper input validation and output encoding mechanisms to prevent similar issues in other applications. The remediation process should involve thorough code review of the private.php script and related components to ensure all user inputs are properly sanitized before processing. Additionally, implementing a Content Security Policy (CSP) can provide an additional layer of protection against XSS attacks by restricting the sources from which scripts can be loaded. Security teams should also consider deploying web application firewalls to monitor and block suspicious requests targeting known vulnerable parameters. This vulnerability demonstrates the critical importance of input validation and output sanitization in web applications, aligning with the ATT&CK technique T1059.007 for Command and Scripting Interpreter and T1566.001 for Phishing, as attackers can use such vulnerabilities to establish persistent access through malicious scripts that execute in user browsers.