CVE-2018-4133 in Safari
Summary
by MITRE
An issue was discovered in certain Apple products. Safari before 11.1 is affected. The issue involves the "WebKit" component. A Safari cross-site scripting (XSS) vulnerability allows remote attackers to inject arbitrary web script or HTML via a crafted URL.
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Analysis
by VulDB Data Team • 02/08/2021
The vulnerability identified as CVE-2018-4133 represents a critical cross-site scripting flaw within Apple's WebKit rendering engine that affected Safari browsers prior to version 11.1. This vulnerability resides in the core web browser component responsible for processing and displaying web content, making it a fundamental security risk for users relying on Apple's Safari browser for web navigation. The flaw specifically manifests when the browser processes specially crafted URLs that contain malicious script payloads, creating a persistent vector for remote code execution and user data compromise.
The technical nature of this vulnerability stems from insufficient input validation and sanitization within the WebKit component's URL handling mechanisms. Attackers can exploit this weakness by crafting malicious URLs that contain embedded JavaScript or HTML code, which the vulnerable Safari browser will execute without proper security checks. This type of vulnerability falls under CWE-79 which specifically addresses cross-site scripting flaws where web applications fail to properly validate or escape user-controllable data. The vulnerability allows attackers to inject arbitrary web scripts into web pages viewed by other users, potentially leading to session hijacking, data theft, or further exploitation of the victim's browser environment.
The operational impact of CVE-2018-4133 extends beyond simple script injection as it creates a persistent threat vector that can be leveraged for sophisticated attacks. Remote attackers can craft URLs that appear legitimate to users while silently executing malicious code in the context of the victim's browser session. This vulnerability particularly affects users who browse the web without proper security awareness or protection mechanisms, as the attack can occur simply through clicking on a malicious link. The vulnerability's impact is amplified by the fact that it affects a widely used browser component that processes millions of URLs daily, making it an attractive target for cybercriminals seeking scalable attack vectors.
Mitigation strategies for this vulnerability require immediate browser updates to version 11.1 or later where Apple has implemented proper input validation and sanitization measures for URL processing. Security administrators should also implement comprehensive web filtering solutions that can detect and block known malicious URL patterns, along with user education programs that emphasize the importance of avoiding suspicious links. Organizations should consider implementing content security policies that limit script execution within browser environments and deploy network monitoring solutions capable of detecting anomalous URL patterns. Additionally, the vulnerability highlights the importance of following ATT&CK framework techniques related to initial access through malicious links, where attackers leverage browser vulnerabilities to establish footholds within target environments. The remediation process should include thorough testing of updated browser versions to ensure that the fix properly addresses the underlying validation issues while maintaining normal browser functionality and user experience.