CVE-2007-0706 in Darksky RSS bar
Summary
by MITRE
Cross-zone scripting vulnerability in Darksky RSS bar for Internet Explorer before 1.29, RSS bar for Sleipnir before 1.29, and RSS bar for unDonut before 1.29 allows remote attackers to bypass Web content zone restrictions via certain script contained in RSS data. NOTE: some of these details are obtained from third party information.
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Analysis
by VulDB Data Team • 10/13/2017
This vulnerability represents a critical cross-zone scripting flaw that specifically targets Internet Explorer browsers and their associated RSS bar extensions. The issue affects multiple browser extensions including Darksky RSS bar, RSS bar for Sleipnir, and RSS bar for unDonut, all versions prior to 1.29. The vulnerability operates by exploiting the way these extensions handle RSS data, allowing malicious actors to inject scripts that can bypass the browser's security zone restrictions. This type of attack falls under the category of cross-zone scripting as defined in CWE-94, where code execution occurs across different security zones within the browser environment.
The technical implementation of this vulnerability leverages the trust relationships between different zones in Internet Explorer's security model. When these RSS extensions process external data feeds, they fail to properly sanitize or validate the script content contained within RSS feeds. This allows attackers to inject malicious JavaScript code that can execute with the privileges of the higher-privileged zone, effectively breaking down the security boundaries that separate trusted and untrusted content. The vulnerability specifically targets the RSS bar extensions' handling of script tags and executable content within feed data, enabling attackers to execute arbitrary code in contexts where such execution would normally be restricted.
The operational impact of this vulnerability is significant as it provides remote attackers with the ability to bypass fundamental web security mechanisms that protect users from malicious content. Attackers can craft malicious RSS feeds that, when processed by the vulnerable extensions, will execute scripts in the context of the user's browser with elevated privileges. This could potentially lead to full system compromise, data theft, or the installation of additional malware. The attack vector is particularly dangerous because it leverages legitimate RSS feed functionality to deliver malicious payloads, making detection more difficult for users and security systems. This vulnerability directly relates to ATT&CK technique T1059.007 for Scripting and T1566.001 for Phishing, as it enables attackers to deliver malicious scripts through seemingly legitimate feed content.
The affected products represent a specific class of browser extensions that process external data feeds without proper security validation. These extensions typically operate in a more permissive security zone to enable their functionality but fail to implement proper input sanitization when processing RSS data. The vulnerability exists because these extensions trust the content of RSS feeds without sufficient validation, allowing attackers to embed malicious scripts that execute in the context of the user's browser. The security implications extend beyond the immediate execution of malicious code, as successful exploitation could lead to persistent compromise of user systems and potential lateral movement within networks. Organizations using these vulnerable extensions should implement immediate mitigations including disabling the extensions, updating to patched versions, or implementing network-level controls to block malicious RSS feeds that could exploit this vulnerability.