CVE-2009-4459 in Redmine
Summary
by MITRE
Redmine 0.8.7 and earlier uses the title tag before defining the character encoding in a meta tag, which allows remote attackers to conduct cross-site scripting (XSS) attacks and inject arbitrary script via UTF-7 encoded values in the title parameter to a new issue page, which may be interpreted as script by Internet Explorer 7 and 8.
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Analysis
by VulDB Data Team • 01/26/2019
The vulnerability identified as CVE-2009-4459 affects Redmine versions 0.8.7 and earlier, presenting a critical cross-site scripting flaw that exploits the order of HTML meta tag definitions. This issue specifically targets the new issue page functionality where the title parameter is processed without proper encoding validation, creating an avenue for malicious actors to inject harmful scripts. The vulnerability stems from the application's improper HTML structure where the title tag is rendered before the character encoding meta tag, a configuration that creates parsing inconsistencies in certain web browsers.
The technical flaw manifests when Internet Explorer 7 and 8 encounter UTF-7 encoded values in the title parameter, as these browsers interpret the encoding differently than modern standards. This parsing behavior allows attackers to craft malicious payloads that bypass standard XSS filtering mechanisms, as the browser's interpretation of the UTF-7 encoding creates a scenario where script content can be injected into the page without triggering typical security filters. The vulnerability operates under CWE-79 which categorizes improper neutralization of input during web page generation, specifically addressing cross-site scripting weaknesses in web applications.
The operational impact of this vulnerability is significant as it enables remote attackers to execute arbitrary scripts within the context of a victim's browser session. This allows for session hijacking, data theft, and potential privilege escalation within the Redmine environment. Attackers can exploit this vulnerability to inject malicious JavaScript that can redirect users to phishing sites, steal authentication cookies, or manipulate the application's functionality to perform unauthorized actions. The attack vector is particularly dangerous because it targets the application's core issue creation functionality, which is frequently used by legitimate users, making the exploitation more likely to succeed.
Security mitigations for this vulnerability include immediate upgrading to Redmine versions that address the HTML rendering order issue and proper input validation for title parameters. Organizations should implement strict encoding validation for all user-supplied input, particularly in web application frameworks that generate HTML content dynamically. The solution requires ensuring that character encoding meta tags are defined before any content that might be interpreted as script, following the principle of secure HTML generation practices. Additionally, implementing Content Security Policy headers can provide defense-in-depth against such XSS attacks by restricting script execution and controlling how resources are loaded within the application context. This vulnerability highlights the importance of proper HTML structure and encoding management in web applications, aligning with ATT&CK technique T1212 which addresses exploitation of encoding and escaping mechanisms in web applications.