CVE-2007-3670 in Chrome
Summary
by MITRE
Argument injection vulnerability in Microsoft Internet Explorer, when running on systems with Firefox installed and certain URIs registered, allows remote attackers to conduct cross-browser scripting attacks and execute arbitrary commands via shell metacharacters in a (1) FirefoxURL or (2) FirefoxHTML URI, which are inserted into the command line that is created when invoking firefox.exe. NOTE: it has been debated as to whether the issue is in Internet Explorer or Firefox. As of 20070711, it is CVE s opinion that IE appears to be failing to properly delimit the URL argument when invoking Firefox, and this issue could arise with other protocol handlers in IE as well. However, Mozilla has stated that it will address the issue with a "defense in depth" fix that will "prevent IE from sending Firefox malicious data."
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Analysis
by VulDB Data Team • 01/13/2025
This vulnerability represents a complex argument injection flaw in Microsoft Internet Explorer that exploits the interaction between web browsers and protocol handlers. The issue manifests when Internet Explorer encounters specific URI schemes such as FirefoxURL or FirefoxHTML and attempts to invoke the Firefox browser executable. The vulnerability stems from improper handling of command line arguments when IE constructs the execution string for firefox.exe, creating a dangerous environment where shell metacharacters can be injected and executed. This type of vulnerability falls under CWE-74 which describes "Improper Neutralization of Special Elements in Output Used by a Downstream Component" and specifically relates to CWE-88 which addresses "Argument Injection." The security implications are particularly severe because they enable cross-browser scripting attacks that can bypass traditional browser security boundaries.
The technical exploitation occurs through the manipulation of URI schemes that are registered in the Windows operating system. When Internet Explorer processes a FirefoxURL or FirefoxHTML URI, it constructs a command line that includes the target URL as an argument to the firefox.exe executable. If the URL contains shell metacharacters such as semicolons, ampersands, or other special characters, these can be interpreted by the command shell as additional commands rather than as part of the URL parameter. This allows remote attackers to inject malicious commands that execute with the privileges of the user running Firefox, potentially leading to arbitrary code execution on the target system. The attack vector specifically leverages the trust relationship between different browser components and the operating system's protocol handler registration system.
The operational impact of this vulnerability extends beyond simple command execution to encompass broader security implications for web browsing environments. Attackers can leverage this weakness to perform sophisticated attacks that combine cross-browser exploitation techniques with traditional shell injection methods. The vulnerability demonstrates a critical flaw in how Internet Explorer handles external protocol invocation, potentially affecting any application that registers protocol handlers in Windows. This issue has been classified under the ATT&CK framework as T1059.007 for "Command and Scripting Interpreter: PowerShell" and T1059.003 for "Command and Scripting Interpreter: Windows Command Shell" due to the shell command injection nature of the exploit. The security community has noted that this vulnerability could potentially be extended to other protocol handlers in IE, making it a systemic issue rather than an isolated incident.
Mitigation strategies for this vulnerability require a multi-layered approach that addresses both the immediate exploitation vectors and the underlying architectural issues. System administrators should implement strict protocol handler restrictions and disable unnecessary URI schemes that could be exploited in similar ways. The recommended defense-in-depth approach involves both browser-level hardening and operating system-level controls to prevent improper argument handling. Microsoft has addressed this issue through security updates that improved the argument delimiting mechanisms in Internet Explorer, while Mozilla has implemented protective measures in Firefox to prevent malicious data injection. Organizations should also deploy web application firewalls and network monitoring solutions to detect and prevent exploitation attempts, particularly focusing on unusual command line patterns and suspicious URI handling behavior. The vulnerability underscores the importance of proper input validation and argument sanitization in cross-platform applications and protocol handler implementations.