CVE-2009-3013 in Web Browser
Summary
by MITRE
Opera 9.52 and earlier, and 10.00 Beta 3 Build 1699, does not properly block data: URIs in Location headers in HTTP responses, which allows remote attackers to conduct cross-site scripting (XSS) attacks via vectors related to (1) injecting a Location 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 Location header. NOTE: the JavaScript executes outside of the context of the HTTP site.
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Analysis
by VulDB Data Team • 08/20/2021
The vulnerability described in CVE-2009-3013 represents a critical cross-site scripting flaw in Opera web browsers version 9.52 and earlier, as well as version 10.00 Beta 3 Build 1699. This security issue stems from Opera's inadequate handling of data: URIs within HTTP Location headers, creating a pathway for remote attackers to execute malicious JavaScript code outside the normal security context of the originating website. The flaw specifically exploits the browser's failure to properly sanitize or block data: URIs that appear in HTTP response Location headers, which should typically redirect users to legitimate web resources.
The technical implementation of this vulnerability involves two primary attack vectors that leverage the browser's URI handling mechanisms. Attackers can manipulate HTTP responses to include Location headers containing data:text/html URIs that embed JavaScript code, or they can directly specify such URIs when constructing Location header content. This allows malicious actors to bypass the normal security boundaries that typically isolate content from different origins, effectively executing JavaScript code in a context that has no relationship to the original HTTP site. The vulnerability essentially permits the browser to interpret and execute arbitrary code from a data URI without proper security checks that would normally occur when processing regular web addresses.
The operational impact of this vulnerability is significant as it enables sophisticated cross-site scripting attacks that can bypass traditional security measures such as same-origin policies. When a user encounters a malicious HTTP response containing a crafted Location header with a data:text/html URI, Opera will process this URI as a legitimate navigation target, executing the embedded JavaScript outside the normal security context of the originating website. This creates a dangerous situation where attackers can inject malicious code that operates with elevated privileges and can potentially access user sessions, steal sensitive information, or perform actions on behalf of the user. The vulnerability is particularly concerning because it operates outside the typical HTTP site context, making it difficult to detect and defend against using conventional web security mechanisms.
This vulnerability aligns with CWE-79, which describes cross-site scripting flaws where untrusted data is improperly handled in web applications. The issue also maps to ATT&CK technique T1059.007 for script execution and T1566 for social engineering attacks that leverage browser vulnerabilities. The attack surface is particularly wide as it can be exploited through various means including malicious web servers, compromised websites, or even through man-in-the-middle attacks that modify HTTP responses. Organizations and users should prioritize updating to newer versions of Opera where this vulnerability has been addressed, as the flaw represents a fundamental breakdown in the browser's URI processing and security boundary enforcement mechanisms. The vulnerability demonstrates the importance of proper input validation and the need for browsers to maintain strict security boundaries even when processing seemingly benign HTTP headers such as Location headers.