CVE-2017-7038 in Safari
Summary
by MITRE
A DOMParser XSS issue was discovered in certain Apple products. iOS before 10.3.3 is affected. Safari before 10.1.2 is affected. tvOS before 10.2.2 is affected. The issue involves the "WebKit" component.
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Analysis
by VulDB Data Team • 01/05/2021
The vulnerability identified as CVE-2017-7038 represents a cross-site scripting flaw within the WebKit rendering engine component of Apple's ecosystem. This issue specifically affects DOMParser functionality which is used to parse XML and HTML content from strings within web applications. The vulnerability stems from insufficient input validation and sanitization mechanisms within the WebKit parser, allowing maliciously crafted content to bypass security checks and execute arbitrary scripts in the context of the affected web page.
The technical flaw manifests when WebKit processes XML or HTML content through the DOMParser API without proper sanitization of user-supplied data. This creates an opportunity for attackers to inject malicious JavaScript code that gets executed when the parsed content is rendered in the browser. The vulnerability is particularly dangerous because DOMParser is commonly used in web applications to dynamically generate content from external sources, making it a prime target for exploitation. The flaw exists in the parsing logic where the system fails to properly escape or validate characters that could be interpreted as executable code, creating a pathway for script injection attacks.
The operational impact of this vulnerability across Apple's affected products is significant given the widespread use of these operating systems. iOS versions before 10.3.3, Safari versions before 10.1.2, and tvOS versions before 10.2.2 all present attack surfaces where users could be exposed to malicious payloads. The vulnerability allows attackers to execute arbitrary JavaScript code in the context of a web page, potentially leading to session hijacking, data theft, or full system compromise. This aligns with CWE-79 which categorizes cross-site scripting vulnerabilities as weaknesses in input validation and output encoding. The attack surface is particularly concerning as it affects not just mobile devices but also television platforms, expanding the potential threat landscape.
Security professionals should note that this vulnerability demonstrates the importance of proper input validation in web rendering components. The issue falls under the ATT&CK framework's technique T1211 for exploitation of web applications through client-side vulnerabilities. Organizations should implement immediate mitigation strategies including updating to patched versions of the affected operating systems and web browsers. Additionally, web developers should review their applications for proper sanitization of data fed into DOMParser functions and consider implementing Content Security Policy headers to limit script execution. The vulnerability underscores the critical need for regular security updates and proper input validation in all web application components to prevent similar issues from occurring in the future.
This vulnerability represents a classic example of how seemingly benign parsing functions can become attack vectors when proper security measures are not implemented. The remediation process requires coordinated updates across multiple Apple platforms, highlighting the interconnected nature of modern mobile and web ecosystems. Security teams should monitor for similar vulnerabilities in other parsing components and ensure comprehensive testing of input validation mechanisms in all web applications. The incident serves as a reminder of the ongoing need for vigilance in web security practices, particularly in browser rendering engines that handle diverse content types from potentially untrusted sources.