CVE-2017-13892 in macOS
Summary
by MITRE • 12/23/2021
An issue existed in the handling of Contact sharing. This issue was addressed with improved handling of user information. This issue is fixed in macOS High Sierra 10.13.2, Security Update 2017-002 Sierra, and Security Update 2017-005 El Capitan. Sharing contact information may lead to unexpected data sharing.
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Analysis
by VulDB Data Team • 12/27/2021
The vulnerability described in CVE-2017-13892 represents a critical flaw in macOS contact sharing mechanisms that could potentially expose user information to unintended recipients. This issue specifically affected the handling of contact data within the operating system's sharing functionality, where proper validation and sanitization of user information was insufficient to prevent unauthorized data disclosure. The vulnerability existed in versions of macOS prior to the security updates released in 2017, creating a window of opportunity for attackers to exploit improper contact sharing protocols that could result in sensitive personal information being inadvertently shared with unauthorized parties.
The technical flaw manifests in the insufficient validation of contact data during the sharing process, where user information could be improperly transmitted or displayed to recipients who should not have access to such data. This type of vulnerability falls under the broader category of information exposure issues that are commonly classified as CWE-200, which deals with exposure of sensitive information to unintended actors. The flaw represents a breakdown in the principle of least privilege where contact sharing mechanisms failed to properly enforce access controls and data boundaries that should have prevented unauthorized information disclosure. The improper handling of user information during contact sharing operations created a scenario where sensitive personal data could flow through the system without adequate safeguards.
The operational impact of this vulnerability extends beyond simple data exposure to encompass potential privacy violations and information leakage that could affect users' personal and professional relationships. When contact information is shared unexpectedly, it can lead to social engineering attacks where attackers exploit the leaked information to conduct targeted phishing campaigns or other malicious activities. The vulnerability particularly affects users who rely on macOS for business communications, as contact sharing is a fundamental feature of the operating system's collaboration capabilities. The risk is amplified when considering that contact sharing often involves sensitive information such as email addresses, phone numbers, physical addresses, and other personally identifiable information that could be leveraged for identity theft or other malicious purposes.
The remediation for this vulnerability required comprehensive updates to the macOS operating system's contact sharing mechanisms, with specific patches released for different versions including macOS High Sierra 10.13.2, Security Update 2017-002 for Sierra, and Security Update 2017-005 for El Capitan. These updates implemented improved handling of user information through enhanced validation procedures and stricter access controls during contact sharing operations. Organizations should prioritize deployment of these security updates to protect against potential exploitation of this vulnerability, as the fixes address fundamental flaws in how contact data is processed and transmitted within the system. The mitigation strategy aligns with the ATT&CK framework's concept of privilege escalation and information gathering techniques, where proper patch management becomes critical in preventing attackers from exploiting these information exposure vulnerabilities. Users should also be educated about the importance of keeping their systems updated and understanding the potential risks associated with sharing contact information in potentially insecure environments.