CVE-2017-2371 in iOS
Summary
by MITRE
An issue was discovered in certain Apple products. iOS before 10.2.1 is affected. The issue involves the "WebKit" component, which allows remote attackers to launch popups via a crafted web site.
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Analysis
by VulDB Data Team • 07/03/2025
The vulnerability identified as CVE-2017-2371 represents a significant security flaw within Apple's WebKit rendering engine that affected iOS versions prior to 10.2.1. This issue resides within the web browser component that powers Safari and other applications utilizing WebKit, creating a pathway for malicious actors to exploit user interactions with compromised web content. The vulnerability specifically targets the popup management functionality within WebKit, which is designed to control how web applications can open new browser windows or tabs. Attackers can craft malicious websites that trigger unauthorized popup windows without user consent or awareness, potentially leading to phishing attacks, malicious content delivery, or user interface deception. The flaw demonstrates a critical failure in the browser's security model where legitimate popup restrictions are bypassed through crafted web content.
This vulnerability operates through a specific technical mechanism that leverages WebKit's popup handling routines to execute unauthorized popup operations. The flaw likely stems from insufficient validation of popup requests within the WebKit engine, allowing crafted JavaScript or HTML content to circumvent normal security boundaries that should prevent automatic popup generation. When users navigate to malicious websites, the compromised code can trigger popup windows that appear to originate from trusted sources while actually delivering malicious payloads or phishing interfaces. The vulnerability's impact extends beyond simple annoyance as it can be weaponized to create convincing social engineering attacks where popup windows mimic legitimate browser dialogs or application interfaces. This particular weakness aligns with CWE-611, which addresses improper access control in web applications, and represents a failure in input validation within the browser's security architecture. The attack vector requires only web page access and does not necessitate additional privileges or complex exploitation techniques.
The operational impact of CVE-2017-2371 creates substantial risk for iOS users who browse the internet regularly, particularly in environments where they may encounter malicious websites through email attachments, social media links, or compromised web services. Users may unknowingly trigger popup windows that appear legitimate while actually containing malicious content, phishing forms, or advertisements designed to harvest personal information. The vulnerability can be exploited in various contexts including mobile banking, email clients, and general web browsing scenarios where users might not immediately recognize the malicious nature of popup windows. Security researchers have noted that this type of vulnerability can serve as a stepping stone for more sophisticated attacks, as the initial popup exploitation can establish a foothold for additional malicious activities. The issue particularly affects mobile users who rely on iOS devices for sensitive activities like online banking, email communication, and accessing corporate resources, where unauthorized popup windows could be used to capture credentials or deliver malware. This vulnerability also demonstrates the broader challenge of browser security where client-side components must maintain strict boundaries between legitimate web content and potentially harmful interactions.
Organizations and individual users should immediately update to iOS 10.2.1 or later versions to remediate this vulnerability, as Apple released this update specifically to address the WebKit popup handling issue. System administrators should ensure all iOS devices within their networks are updated through proper mobile device management solutions, particularly in enterprise environments where users may be accessing sensitive corporate data through mobile browsers. Additional mitigations include implementing web content filtering solutions that can detect and block known malicious popup patterns, as well as educating users about the risks of visiting untrusted websites and the importance of recognizing potentially malicious popup windows. Security monitoring should include detection of unusual popup behavior patterns that may indicate exploitation attempts, and network administrators should consider implementing browser security policies that restrict popup functionality in enterprise environments. The vulnerability serves as a reminder of the importance of maintaining current security patches and the potential risks associated with outdated browser components that may contain unpatched security flaws. Organizations should also consider implementing additional security layers including browser sandboxing, content security policies, and regular security assessments of mobile applications and web browsing activities to prevent exploitation of similar vulnerabilities.