CVE-2017-2508 in Safari
Summary
by MITRE
An issue was discovered in certain Apple products. iOS before 10.3.2 is affected. Safari before 10.1.1 is affected. The issue involves the "WebKit" component. It allows remote attackers to conduct Universal XSS (UXSS) attacks via a crafted web site that improperly interacts with container nodes.
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Analysis
by VulDB Data Team • 08/24/2024
The vulnerability identified as CVE-2017-2508 represents a critical cross-site scripting flaw within Apple's WebKit rendering engine that affected multiple iOS and Safari versions. This security weakness exists in the way WebKit processes container nodes within web pages, creating a pathway for remote attackers to execute malicious scripts across different contexts. The vulnerability specifically impacts iOS versions prior to 10.3.2 and Safari versions before 10.1.1, making a significant portion of Apple's mobile and desktop browser ecosystem susceptible to exploitation. The flaw operates at the core rendering layer of web content, where improper handling of container nodes creates opportunities for attackers to bypass traditional security mechanisms that typically protect against cross-site scripting attacks.
The technical nature of this vulnerability stems from WebKit's inadequate validation of container node interactions within the Document Object Model. When a malicious website constructs web content using specific patterns that manipulate container elements, the browser's rendering engine fails to properly isolate these elements, allowing attacker-controlled scripts to execute in contexts where they should be restricted. This universal cross-site scripting vulnerability operates by exploiting the way WebKit manages the relationship between different DOM nodes and their associated event handlers, creating a scenario where a script injected into one container element can propagate to other container nodes within the same document context. The vulnerability falls under CWE-79, which specifically addresses cross-site scripting flaws, but with the added complexity of universal exploitation across different container contexts rather than traditional single-site attacks.
The operational impact of CVE-2017-2508 extends beyond typical web-based attacks, as it enables attackers to conduct sophisticated Universal XSS attacks that can bypass standard browser security controls. This type of attack allows threat actors to inject malicious scripts that can access sensitive user data, manipulate browser functionality, and potentially escalate privileges within the browser environment. The vulnerability's exploitation requires a crafted website that carefully constructs container node interactions to trigger the underlying flaw, making it particularly dangerous as it can be delivered through seemingly legitimate web pages. Attackers can leverage this vulnerability to steal session cookies, perform unauthorized actions on behalf of users, or redirect users to malicious sites without their knowledge. The implications are particularly severe given that WebKit powers not only Safari but also numerous applications and embedded browsers within Apple's ecosystem, potentially affecting a wide range of services and user activities.
Mitigation strategies for this vulnerability require immediate patching of affected systems to upgrade to iOS 10.3.2 or later versions and Safari 10.1.1 or later. Organizations should implement comprehensive browser security policies that include regular updates and monitoring for vulnerable versions. The fix addresses the underlying container node handling within WebKit by strengthening the validation mechanisms that prevent cross-context script execution. Security teams should also consider implementing additional protective measures such as content security policies and browser hardening configurations to reduce the potential impact of similar vulnerabilities. This vulnerability demonstrates the importance of maintaining up-to-date browser security patches and highlights the critical nature of rendering engine vulnerabilities that can affect the entire web browsing experience. The ATT&CK framework categorizes this as a web-based exploitation technique under the application layer, emphasizing the need for robust browser security controls and regular security assessments to identify and remediate similar vulnerabilities in web rendering components.