CVE-2006-0770 in MyBB
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in calendar.php in MyBulletinBoard (MyBB) 1.0.4 allows remote attackers to inject arbitrary web script or HTML via a URL that is not sanitized before being returned as a link in "advanced details". NOTE: the provenance of this information is unknown; the details are obtained solely from third party information.
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Analysis
by VulDB Data Team • 04/30/2019
The vulnerability described in CVE-2006-0770 represents a classic cross-site scripting flaw within the MyBulletinBoard 1.0.4 web application, specifically affecting the calendar.php component. This type of vulnerability falls under the broader category of CWE-79 Improper Neutralization of Input During Web Page Generation, which is a fundamental weakness in web application security where user-supplied data is not properly sanitized before being rendered in web pages. The vulnerability manifests when the application fails to validate or escape user input that is subsequently displayed in the context of a web page, creating an avenue for malicious actors to execute arbitrary scripts within the victim's browser context.
The technical flaw occurs within the calendar.php script where URLs provided by users are not adequately sanitized before being processed and returned as clickable links in the "advanced details" section of the calendar functionality. This oversight allows attackers to craft malicious URLs containing embedded script code that gets executed when other users view the calendar page. The vulnerability specifically affects the application's handling of user-provided URL parameters that are directly incorporated into HTML link elements without proper input validation or output encoding. Attackers can exploit this by submitting crafted URLs containing javascript: protocols or html entities that execute malicious code when the affected page renders.
The operational impact of this vulnerability extends beyond simple script execution, as it enables attackers to perform various malicious activities within the context of authenticated users' sessions. An attacker could potentially steal session cookies, redirect users to phishing sites, deface the bulletin board, or perform actions on behalf of users with the privileges of the targeted account. The vulnerability's exploitation is particularly concerning because it leverages the trust relationship between the web application and its users, allowing malicious code to execute in the context of legitimate user sessions. This creates a persistent threat vector that can be exploited repeatedly without requiring additional authentication or privileged access to the application's backend systems.
Mitigation strategies for this vulnerability should focus on implementing proper input validation and output encoding practices. The primary remediation involves sanitizing all user-provided input before it is processed or displayed in web pages, particularly when incorporating data into HTML attributes such as href links. Organizations should implement strict validation of URL formats and sanitize any input that will be rendered in HTML contexts. Additionally, the implementation of Content Security Policy headers can provide an additional layer of protection by restricting the sources from which scripts can be executed. The vulnerability also highlights the importance of regular security audits and the need for developers to follow secure coding practices as outlined in the OWASP Top Ten and other industry standards. According to ATT&CK framework, this vulnerability maps to T1566.001 Initial Access: Phishing, as attackers can leverage this flaw to deliver malicious payloads through crafted calendar entries that users may encounter during normal browsing activities.