CVE-2017-16012 in jQuery
Summary
by MITRE
Jquery is a javascript library for DOM traversal and manipulation, event handling, animation, and Ajax. When text/javascript responses are received from cross-origin ajax requests not containing the option `dataType`, the result is executed in `jQuery.globalEval` potentially allowing an attacker to execute arbitrary code on the origin. This affects Jquery >=1.4.0 <=1.11.3 || >=1.12.4 <=2.2.4.
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Analysis
by VulDB Data Team • 03/21/2023
This vulnerability represents a critical cross-site scripting flaw in the jQuery JavaScript library that enables remote code execution through improper handling of cross-origin ajax responses. The issue stems from how jQuery processes text/javascript content returned from cross-origin requests when no explicit dataType parameter is specified, creating a dangerous execution path that can be exploited by malicious actors. The vulnerability affects multiple versions of jQuery including the 1.x series from 1.4.0 through 1.11.3 and the 2.x series from 1.12.4 through 2.2.4, indicating a prolonged period of exposure across the library's development lifecycle. This flaw directly maps to CWE-94, which describes the execution of potentially malicious code, and falls under the broader category of insecure deserialization and code injection vulnerabilities.
The technical exploitation occurs when jQuery receives a text/javascript response from a cross-origin ajax request without explicitly defining the dataType parameter. In such cases, the library automatically executes the returned content through the jQuery.globalEval function, which serves as the primary attack vector for this vulnerability. This behavior creates a scenario where an attacker can craft malicious responses that get executed in the context of the victim's browser, effectively allowing arbitrary code execution on the origin domain. The vulnerability is particularly dangerous because it leverages the legitimate cross-origin request functionality of the library, making it difficult to detect through traditional security monitoring approaches. The flaw essentially transforms a legitimate library feature into a weapon for executing unauthorized code, bypassing standard security boundaries that should protect against cross-origin content execution.
The operational impact of this vulnerability extends far beyond simple code execution, as it provides attackers with complete control over the victim's browser session and can lead to data theft, session hijacking, and further exploitation of the affected system. When exploited successfully, an attacker can manipulate the DOM, steal cookies, access sensitive data, and potentially escalate the attack to compromise the entire user session. The vulnerability affects web applications that rely on jQuery for cross-origin communication, making it particularly dangerous in environments where third-party services are integrated. This type of vulnerability is classified under the ATT&CK technique T1059.007 for command and scripting interpreter, specifically targeting JavaScript interpreters, and represents a significant risk to web application security. The widespread adoption of jQuery across web applications means that this vulnerability could potentially affect thousands of websites and applications that depend on the library for client-side functionality.
Organizations should immediately implement mitigation strategies including updating to patched versions of jQuery, implementing strict content security policies, and ensuring that all cross-origin requests explicitly define the dataType parameter to prevent automatic execution. The recommended remediation involves upgrading to jQuery versions 1.12.5, 2.2.5, or 3.2.1 and later, which contain the necessary patches to address this vulnerability. Additionally, security teams should conduct thorough audits of their web applications to identify any remaining instances of vulnerable jQuery usage and implement proper input validation and output encoding practices. Organizations should also consider implementing web application firewalls and monitoring for suspicious cross-origin request patterns to detect potential exploitation attempts. The vulnerability serves as a reminder of the critical importance of proper input validation and secure coding practices in client-side libraries, as even well-established libraries can contain dangerous execution paths that can be exploited by threat actors.