CVE-2020-7656 in PeopleSoft Enterprise PeopleTools
Summary
by MITRE
jquery prior to 1.9.0 allows Cross-site Scripting attacks via the load method. The load method fails to recognize and remove "" HTML tags that contain a whitespace character, i.e: "", which results in the enclosed script logic to be executed.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 04/11/2025
The vulnerability identified as CVE-2020-7656 represents a critical cross-site scripting flaw in jQuery versions prior to 1.9.0 that specifically affects the load method implementation. This vulnerability stems from inadequate input validation and sanitization mechanisms within the library's handling of HTML content, creating a pathway for malicious actors to inject and execute arbitrary script code within victim browsers. The flaw exploits the library's failure to properly sanitize HTML tags that contain whitespace characters, particularly those that appear before the closing bracket of script tags. This weakness allows attackers to bypass standard security measures by embedding whitespace characters within the HTML structure, effectively evading traditional XSS detection mechanisms that rely on strict pattern matching. The vulnerability operates at the application layer and can be classified under CWE-79 Improper Neutralization of Input During Web Page Generation, which specifically addresses the failure to properly escape or sanitize user-provided data that gets rendered in web pages.
The technical exploitation of this vulnerability occurs when the load method processes HTML content that contains script tags with whitespace characters in their opening brackets. The jQuery library's parser fails to recognize these malformed script tags as potentially dangerous, treating them as legitimate HTML elements instead of malicious payloads. This parsing error creates a condition where attacker-controlled HTML content can be loaded into web pages without proper sanitization, leading to the execution of embedded JavaScript code. The vulnerability is particularly concerning because it affects a widely used JavaScript library that powers millions of websites, making it a prime target for mass exploitation. Attackers can craft malicious payloads that appear harmless to traditional security scanners but contain whitespace characters that trigger the vulnerability. This weakness directly maps to ATT&CK technique T1203 Exploitation for Client Execution, where adversaries leverage vulnerabilities in client-side applications to execute malicious code. The attack vector typically involves injecting malicious HTML content through user input fields, file uploads, or API endpoints that subsequently utilize the vulnerable load method to process and render content.
The operational impact of CVE-2020-7656 extends far beyond individual website compromises, as it affects the fundamental security posture of web applications that depend on jQuery for dynamic content loading. When exploited, this vulnerability allows attackers to execute arbitrary JavaScript code in the context of the victim's browser session, potentially leading to session hijacking, data theft, credential harvesting, and full account takeovers. The vulnerability's persistence across multiple jQuery versions means that organizations with legacy systems or those unable to immediately upgrade face prolonged exposure to attack. The impact is amplified by the fact that the load method is commonly used for AJAX content loading, making it a frequent target for exploitation in modern web applications. Security teams must consider the cascading effects of this vulnerability, as compromised applications can serve as entry points for broader network infiltration. The vulnerability also affects web application firewalls and other security controls that may not detect the whitespace-based obfuscation technique used by attackers. Organizations relying on jQuery for content loading and dynamic page updates face significant risk of data breaches and service disruption, particularly in environments where user-generated content is processed.
Mitigation strategies for CVE-2020-7656 require immediate action to address the root cause through proper library version management and input sanitization. Organizations should prioritize upgrading to jQuery version 1.9.0 or later, where the vulnerability has been patched through improved HTML parsing and sanitization routines. Additionally, implementing comprehensive input validation and output encoding mechanisms can provide defense-in-depth measures that protect against similar vulnerabilities. Security professionals should deploy content security policies that restrict script execution and implement proper HTML sanitization libraries that can detect and neutralize whitespace-based XSS attempts. Regular security audits and vulnerability assessments should include checks for outdated jQuery versions and other JavaScript libraries that may exhibit similar parsing vulnerabilities. The remediation process must also involve thorough testing of web applications to ensure that the upgrade does not introduce compatibility issues while maintaining security posture. Organizations should establish automated monitoring systems to detect and alert on potentially vulnerable code patterns and maintain updated threat intelligence feeds that track similar vulnerabilities in the JavaScript ecosystem. Implementation of these measures aligns with security best practices outlined in NIST SP 800-53 and ISO 27001 frameworks, which emphasize the importance of maintaining up-to-date software and implementing robust input validation controls.