CVE-2022-26766 in macOS
Summary
by MITRE • 05/27/2022
A certificate parsing issue was addressed with improved checks. This issue is fixed in tvOS 15.5, iOS 15.5 and iPadOS 15.5, Security Update 2022-004 Catalina, watchOS 8.6, macOS Big Sur 11.6.6, macOS Monterey 12.4. A malicious app may be able to bypass signature validation.
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Analysis
by VulDB Data Team • 05/31/2025
The certificate parsing vulnerability identified as CVE-2022-26766 represents a critical security flaw in Apple's operating systems that affects the validation of digital certificates used for code signing and system integrity verification. This issue stems from insufficient input validation during the certificate parsing process, creating potential attack vectors that could allow malicious applications to bypass legitimate signature validation mechanisms. The vulnerability specifically impacts iOS 15.5, iPadOS 15.5, tvOS 15.5, watchOS 8.6, macOS Big Sur 11.6.6, and macOS Monterey 12.4, indicating a widespread impact across Apple's ecosystem of devices and operating systems.
The technical nature of this flaw falls under the category of improper input validation as classified by CWE-20, where the system fails to properly validate or sanitize certificate data before processing. During certificate parsing operations, the affected systems do not adequately check for malformed or maliciously constructed certificate structures that could exploit parsing routines to alter the certificate validation logic. This vulnerability creates a path for attackers to craft specially crafted certificates or manipulate existing certificates in ways that would normally be rejected by proper validation routines, potentially enabling code execution or privilege escalation attacks.
The operational impact of CVE-2022-26766 extends beyond simple bypass of signature validation, as it could enable attackers to install malicious applications that appear legitimate to the system's security mechanisms. This represents a significant threat to device integrity and user security, particularly in enterprise environments where code signing is crucial for maintaining software integrity. The vulnerability could be exploited through various attack vectors including malicious app distribution, supply chain attacks, or by leveraging other vulnerabilities to install compromised applications that would otherwise be rejected by the system's signature validation processes. The attack surface is particularly concerning given that this affects core operating system components that are integral to device security and user protection.
Organizations and users must prioritize immediate deployment of the security updates released by Apple to address this vulnerability, as the window for exploitation remains open until systems are properly patched. The recommended mitigation strategy involves applying the Security Update 2022-004 for macOS Catalina, updating to the specified versions of iOS, iPadOS, tvOS, watchOS, and macOS Big Sur and Monterey releases. Security teams should also implement additional monitoring for suspicious certificate-related activities and consider conducting comprehensive security audits to identify any potential exploitation attempts. The vulnerability aligns with ATT&CK technique T1553.004 for Valid Code Signing Certificates, highlighting the importance of maintaining proper certificate validation mechanisms and ensuring that all code signing processes remain robust against manipulation attempts.