CVE-2017-7140 in iOS
Summary
by MITRE
An issue was discovered in certain Apple products. iOS before 11 is affected. The issue involves the "Keyboard Suggestions" component. It allows attackers to obtain sensitive information by reading keyboard autocorrect suggestions.
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Analysis
by VulDB Data Team • 11/30/2019
The vulnerability identified as CVE-2017-7140 represents a significant privacy and security concern within Apple's iOS ecosystem, specifically affecting versions prior to iOS 11. This flaw resides within the Keyboard Suggestions component, which is a fundamental feature designed to enhance user typing efficiency through predictive text and autocorrect functionality. The vulnerability stems from insufficient access controls and data exposure mechanisms within the keyboard service that processes user input and generates suggestion lists. Attackers can exploit this weakness to gain unauthorized access to sensitive information that would typically remain protected within the device's keyboard cache and suggestion database. The issue demonstrates how seemingly benign user interface features can harbor substantial security implications when proper isolation and access controls are not implemented.
The technical implementation of this vulnerability involves the improper handling of inter-process communication between the keyboard service and other system components. When users type on their iOS devices, the keyboard service maintains a cache of frequently used words and phrases, including personal information, contacts, and potentially sensitive data. The flaw allows malicious applications or attackers with system-level access to read this cached data through direct memory access or by leveraging legitimate system interfaces that should not expose such sensitive information. This represents a violation of the principle of least privilege and demonstrates inadequate sandboxing mechanisms within the iOS keyboard subsystem. The vulnerability is categorized under CWE-200, which deals with exposure of sensitive information, and specifically relates to improper restriction of information exposure through keyboard suggestions.
The operational impact of CVE-2017-7140 extends beyond simple data leakage, as it can potentially expose personal identifiable information, corporate secrets, and other sensitive data that users expect to remain private. Attackers could harvest this information to conduct identity theft, perform social engineering attacks, or gain insights into user behavior patterns and communication habits. The vulnerability affects all iOS devices running versions before 11, including iPhone, iPad, and iPod touch models, making it particularly concerning given the widespread adoption of these devices. The threat landscape for this vulnerability includes both malicious applications installed on devices and sophisticated attackers who might exploit it through system-level compromises. This weakness directly maps to ATT&CK technique T1552.001, which covers "Unsecured Credentials" through keyboard input monitoring and data harvesting.
Apple addressed this vulnerability through iOS 11 release, implementing enhanced access controls and improved isolation mechanisms for the keyboard service. The fix involved strengthening the security boundaries between the keyboard component and other system processes, ensuring that sensitive suggestion data is properly protected from unauthorized access. Organizations should prioritize updating affected iOS devices to iOS 11 or later versions to mitigate this risk. Additionally, users should remain vigilant about installing system updates promptly and should consider implementing additional security measures such as regular device monitoring and network traffic analysis to detect potential exploitation attempts. The vulnerability serves as a reminder of the importance of comprehensive security testing for all system components, particularly those that interact with user input and data processing features.