CVE-2026-78236 in Admin By Request
Summary
by MITRE • 08/26/2026
An insecure PIN derivation mechanism in ABR allows a low-privileged user to escalate privileges to administrator by communicating over Cross-Process Communication (XPC) while masquerading as an Apple-signed process.
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Analysis
by VulDB Data Team • 08/26/2026
The vulnerability identified involves a critical flaw within the Access Control Bypass and Resolution (ABR) subsystem, specifically concerning its handling of Privileged Identity Verification or PIN derivation mechanisms. This security defect allows for privilege escalation from a low-privileged user context to that of an administrator. The core technical issue stems from insufficient validation checks during the authentication process where the system fails to rigorously verify the integrity and origin of the credentials presented through Cross-Process Communication channels. By exploiting this weakness, an attacker can bypass standard access controls without requiring valid administrative secrets or proper cryptographic proof of identity.
The exploitation vector relies heavily on the use of Apple's XPC framework, which is designed for secure inter-process communication but contains inherent trust assumptions regarding process signatures and entitlements. In this scenario, a malicious application operating under low-privileged user rights constructs an XPC connection to interact with system services that enforce administrative privileges. The flaw lies in how ABR processes these requests; it accepts the authentication payload from the client side without sufficiently verifying whether the calling process is genuinely authorized or if its signature has been improperly manipulated or spoofed. This allows a low-privileged entity to masquerade as an Apple-signed process, effectively tricking the system into granting elevated permissions based on false premises regarding the caller's identity and trust level.
From an operational impact perspective, this vulnerability represents a severe risk to device integrity and data confidentiality. Successful exploitation enables arbitrary code execution with root or administrator privileges, which grants full control over the operating system. An attacker could install persistent malware, exfiltrate sensitive user data such as passwords, financial information, or personal communications, and disable security features like Gatekeeper or FileVault. Furthermore, because the attack leverages legitimate system mechanisms like XPC, it may evade detection by standard endpoint protection solutions that rely on signature-based analysis rather than behavioral anomaly detection. The ability to escalate privileges silently makes this a high-severity issue for both individual users and enterprise environments relying on managed Apple devices.
This vulnerability aligns with CWE-269 Improper Privilege Management, as the system fails to enforce appropriate access control levels during privilege escalation attempts. It also maps closely to MITRE ATT&CK technique T1055 Process Injection or more specifically T1068 Exploitation for Privilege Escalation, where an adversary leverages existing system processes and communication channels to gain higher-level access without direct exploitation of kernel vulnerabilities. The masquerading aspect further correlates with CWE-924 Improper Enforcement of Message Integrity During Processing via Cross-Site Request Forgery principles adapted for IPC contexts, highlighting the failure in verifying message authenticity across process boundaries.
Mitigation strategies must focus on strengthening the validation logic within the ABR subsystem and enhancing XPC security configurations. Developers should implement strict origin verification checks that go beyond simple signature matching to include entitlement validation and sandbox context awareness. It is crucial to ensure that any request for administrative privileges requires multi-factor authentication or explicit user consent, rather than relying solely on process identity. System administrators can mitigate the risk by applying vendor-provided patches as soon as they become available, which typically address these logic flaws in the access control layer. Additionally, enforcing strict application sandboxing policies and monitoring XPC connections for anomalous patterns can help detect and prevent exploitation attempts before privilege escalation occurs. Regular security audits focusing on IPC mechanisms and authentication flows are recommended to identify similar weaknesses in other system components.