CVE-2009-3010 in Firefox
Summary
by MITRE
Mozilla Firefox 3.0.13 and earlier, 3.5, 3.6 a1 pre, and 3.7 a1 pre; SeaMonkey 1.1.17; and Mozilla 1.7.x and earlier do not properly block data: URIs in Refresh headers in HTTP responses, which allows remote attackers to conduct cross-site scripting (XSS) attacks via vectors related to (1) injecting a Refresh header that contains JavaScript sequences in a data:text/html URI or (2) entering a data:text/html URI with JavaScript sequences when specifying the content of a Refresh header. NOTE: in some product versions, the JavaScript executes outside of the context of the HTTP site.
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Analysis
by VulDB Data Team • 01/18/2019
This vulnerability resides in the handling of HTTP Refresh headers within web browsers, specifically affecting Mozilla Firefox versions up to 3.0.13, 3.5, 3.6 a1 pre, and 3.7 a1 pre, along with SeaMonkey 1.1.17 and Mozilla 1.7.x and earlier. The core issue involves the improper blocking of data: URIs in Refresh headers, which creates a pathway for malicious actors to execute cross-site scripting attacks. The flaw occurs when browsers process HTTP responses containing Refresh headers that reference data:text/html URIs, allowing JavaScript code embedded within these URIs to be executed in the context of the victim's browser. This vulnerability represents a classic bypass of web security mechanisms where the browser's URI validation logic fails to properly sanitize or reject data: URIs that contain executable JavaScript content. The technical implementation involves the browser's HTTP response parsing logic not adequately distinguishing between legitimate and malicious data: URIs in Refresh header values, thereby creating an execution environment where arbitrary JavaScript can run with the privileges of the victim's browsing session.
The operational impact of this vulnerability extends beyond simple XSS exploitation as it allows attackers to bypass the same-origin policy that normally protects web applications from cross-site scripting. When JavaScript code executes outside the context of the HTTP site, as noted in the vulnerability description, it means that the malicious script can operate with elevated privileges and access resources that would normally be restricted. This particular vulnerability aligns with CWE-79, which describes cross-site scripting flaws, and demonstrates how improper input validation in HTTP headers can create security boundaries that are easily circumvented. Attackers can leverage this vulnerability by crafting malicious HTTP responses with Refresh headers containing data:text/html URIs that embed JavaScript payloads, effectively allowing them to inject and execute code in the victim's browser without requiring traditional XSS attack vectors such as direct user input manipulation or form submissions.
The security implications of this vulnerability are significant as it enables attackers to perform various malicious activities including session hijacking, credential theft, and data exfiltration. The ability to execute JavaScript outside the normal site context means that attackers can access the victim's browser storage, cookies, and potentially interact with other web applications that the user has authenticated to. This vulnerability also maps to ATT&CK technique T1059.007, which covers JavaScript execution, and represents a critical flaw in browser security architecture that undermines the fundamental isolation principles that web browsers implement. The vulnerability essentially allows for a form of privilege escalation within the browser environment, where attackers can execute code with the same permissions as the legitimate user, making it particularly dangerous for enterprise environments where users may have access to sensitive corporate resources. Organizations using affected browser versions are particularly vulnerable to targeted attacks where attackers can use this flaw to establish persistent access to user sessions and potentially move laterally within networks through compromised user browsers.