CVE-2018-4149 in iOS
Summary
by MITRE
An issue was discovered in certain Apple products. iOS before 11.3 is affected. The issue involves the "SafariViewController" component. It allows remote attackers to spoof the user interface via a crafted web site that leverages input into a partially loaded page.
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Analysis
by VulDB Data Team • 02/06/2021
The vulnerability identified as CVE-2018-4149 represents a significant user interface spoofing flaw within Apple's SafariViewController component affecting iOS versions prior to 11.3. This security weakness resides in the way SafariViewController handles web content rendering and user interface presentation, creating opportunities for malicious actors to manipulate the visual representation of web pages. The vulnerability specifically targets the component's interaction with partially loaded web pages, where the interface elements can be manipulated to deceive users into believing they are interacting with legitimate websites while actually engaging with attacker-controlled content.
The technical implementation of this vulnerability stems from insufficient validation and sanitization of web content within the SafariViewController framework. When a webpage is partially loaded, the component fails to properly distinguish between legitimate interface elements and those that have been crafted by attackers. This allows remote adversaries to inject malicious UI elements that appear to be part of the original website, creating a deceptive user experience that can lead to various security consequences including credential theft, unauthorized transactions, or data exfiltration. The flaw operates at the presentation layer of the web browsing experience, making it particularly dangerous as users may not immediately recognize the spoofed interface elements.
The operational impact of CVE-2018-4149 extends beyond simple phishing attacks, as it can be leveraged in sophisticated social engineering campaigns that exploit user trust in familiar web interfaces. Attackers can craft malicious websites that manipulate the SafariViewController to display fake login forms, payment portals, or other interface elements that appear authentic to users. This vulnerability aligns with CWE-611, which addresses Improper Restriction of XML External Entity Reference, as the flaw involves improper handling of external content that can be manipulated to alter the user interface presentation. The attack vector is particularly concerning as it requires no local privilege escalation and can be executed through standard web browsing activities, making it accessible to threat actors with minimal technical expertise.
From an adversary perspective, this vulnerability maps to several ATT&CK techniques including T1071.001 for Application Layer Protocol: Web Protocols and T1531 for Account Access Through Web Shell, as it enables attackers to create deceptive web interfaces that can harvest user credentials or financial information. The vulnerability's exploitation requires minimal user interaction beyond normal browsing behavior, making it particularly dangerous in environments where users frequently interact with web content through SafariViewController components. Organizations and individuals using affected iOS versions face increased risk of targeted attacks that can bypass traditional security measures, as the spoofing occurs at the interface level where users typically place high trust.
Mitigation strategies for CVE-2018-4149 primarily focus on immediate system updates to iOS 11.3 or later versions where Apple has implemented patches to address the SafariViewController interface handling. Security administrators should also implement network-level monitoring to detect suspicious web traffic patterns that may indicate exploitation attempts, while users should remain vigilant about unusual interface elements during web browsing. Additional protective measures include implementing browser security extensions, conducting regular security awareness training, and establishing incident response procedures specifically addressing UI spoofing attacks. Organizations should also consider deploying web application firewalls and content filtering solutions to provide additional layers of protection against malicious web content that could exploit this vulnerability.