CVE-2011-3000 in Firefox
Summary
by MITRE
Mozilla Firefox before 3.6.23 and 4.x through 6, Thunderbird before 7.0, and SeaMonkey before 2.4 do not properly handle HTTP responses that contain multiple Location, Content-Length, or Content-Disposition headers, which makes it easier for remote attackers to conduct HTTP response splitting attacks via crafted header values.
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Analysis
by VulDB Data Team • 11/20/2021
This vulnerability resides in the HTTP header processing mechanisms of several Mozilla applications including Firefox versions prior to 3.6.23 and 4.x through 6, Thunderbird versions before 7.0, and SeaMonkey versions before 2.4. The flaw specifically manifests when these applications encounter HTTP responses containing multiple instances of critical headers such as Location, Content-Length, or Content-Disposition. This improper handling creates a condition where the applications fail to correctly parse or validate multiple header values, leading to potential security implications that can be exploited by remote attackers.
The technical root cause of this vulnerability can be categorized under CWE-1270, which addresses improper handling of HTTP headers in web browsers. When multiple headers of the same type are present in an HTTP response, the applications should properly process and validate these headers according to HTTP specifications. However, in affected versions, the parsing logic does not adequately distinguish between legitimate multiple header values and maliciously crafted headers designed to exploit the response splitting vulnerability. This behavior creates a pathway for attackers to inject malicious content into HTTP responses, potentially allowing them to manipulate the application's behavior or redirect users to malicious sites.
The operational impact of this vulnerability extends beyond simple header parsing issues and creates significant risks for users of these affected applications. Attackers can leverage this flaw to conduct HTTP response splitting attacks, which can lead to various malicious activities including cross-site scripting attacks, session hijacking, and cache poisoning. The vulnerability is particularly dangerous because it allows attackers to inject arbitrary HTTP headers into responses, potentially bypassing security controls that depend on proper header validation. This makes it easier for attackers to manipulate web application behavior, redirect users to phishing sites, or inject malicious content into web pages that users visit.
The security implications of this vulnerability align with techniques described in the MITRE ATT&CK framework under the T1190 category for Exploit Public-Facing Application, and specifically relates to techniques involving HTTP response manipulation. Organizations using affected versions of these Mozilla applications face increased risk of successful attacks, particularly in environments where users may encounter malicious web content or where the applications are used in enterprise settings with sensitive data. The vulnerability's impact is amplified because these applications are widely used and often serve as the primary interface for web-based communication and email services.
Mitigation strategies for this vulnerability involve immediate upgrade to patched versions of the affected applications, as recommended by Mozilla's security advisories. System administrators should prioritize patching all instances of Firefox 3.6.22 and earlier, Firefox 4.0 through 6.0, Thunderbird 6.0 and earlier, and SeaMonkey 2.3 and earlier. Additionally, network administrators should consider implementing additional security controls such as web application firewalls that can detect and block malformed HTTP headers, though the most effective solution remains the application of official security patches. Organizations should also conduct vulnerability assessments to identify any systems running affected software versions and ensure proper patch management processes are in place to prevent similar issues in the future.