CVE-2010-2809 in Uzbl
Summary
by MITRE
The default configuration of the <Button2> binding in Uzbl before 2010.08.05 does not properly use the @SELECTED_URI feature, which allows user-assisted remote attackers to execute arbitrary commands via a crafted HREF attribute of an A element in an HTML document.
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Analysis
by VulDB Data Team • 01/21/2025
The vulnerability identified as CVE-2010-2809 resides within the Uzbl web browser, a lightweight and extensible browser designed for Unix-like systems. This flaw specifically impacts the default configuration of the Button2 binding, which handles middle-click mouse events in the browser interface. The vulnerability stems from improper handling of the @SELECTED_URI feature, a mechanism intended to provide context-aware URI selection during user interactions. When a user middle-clicks on a hyperlink, the browser should properly interpret and sanitize the URI before processing it, but the vulnerable version fails to adequately validate the selected URI.
The technical exploitation of this vulnerability occurs through a crafted HTML document containing an A element with a specially constructed HREF attribute. When a user middle-clicks on such a malicious link, the browser's handling of the @SELECTED_URI feature becomes compromised, allowing attackers to inject and execute arbitrary commands on the victim's system. This represents a classic command injection vulnerability where the attacker can leverage the browser's interaction with web content to bypass normal security boundaries and execute unauthorized code. The vulnerability operates at the application layer and requires user interaction to be successful, making it a user-assisted remote code execution flaw.
The operational impact of CVE-2010-2809 extends beyond simple command execution, as it can potentially allow attackers to gain full control over the victim's system. Since Uzbl is designed to be highly extensible through external scripts and configuration files, the arbitrary command execution capability could enable attackers to install malware, modify system files, or exfiltrate sensitive data. The vulnerability affects all users running Uzbl versions prior to 2010.08.05, making it particularly concerning for environments where this browser is actively used. The attack vector requires the victim to interact with malicious web content, typically through a phishing email or compromised website, making social engineering a critical component of successful exploitation.
Mitigation strategies for this vulnerability primarily involve upgrading to Uzbl version 2010.08.05 or later, which contains the necessary patches to properly handle the @SELECTED_URI feature. System administrators should also implement web filtering solutions to block access to potentially malicious websites and educate users about the risks of clicking on untrusted links. The vulnerability aligns with CWE-78, which describes improper neutralization of special elements used in OS commands, and can be categorized under ATT&CK technique T1059 for command and scripting interpreter. Organizations should also consider implementing sandboxing mechanisms to limit the potential damage from successful exploitation attempts, as well as monitoring for unusual command execution patterns that might indicate compromise. Regular security audits and vulnerability assessments should include checks for outdated browser installations to prevent similar issues from persisting in the environment.