CVE-2026-24071 in Native Access
Summary
by MITRE • 02/02/2026
It was found that the XPC service offered by the privileged helper of Native Access uses the PID of the connecting client to verify its code signature. This is considered insecure and can be exploited by PID reuse attacks. The connection handler function uses _xpc_connection_get_pid(arg2) as argument for the hasValidSignature function. This value can not be trusted since it is vulnerable to PID reuse attacks.
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Analysis
by VulDB Data Team • 02/12/2026
The vulnerability described in CVE-2026-24071 resides within the Native Access privileged helper service architecture, specifically in how it validates client authenticity through XPC (Cross-Process Communication) mechanisms. This security flaw represents a critical design weakness in the privilege escalation and code integrity verification process. The affected system employs an XPC service that acts as a bridge between user-space applications and privileged helper processes, creating a potential attack surface where malicious actors can exploit fundamental process identification mechanisms.
The technical implementation of this vulnerability stems from the service's reliance on Process Identifier (PID) validation as a security control mechanism. When a client connects to the privileged helper service, the system calls _xpc_connection_get_pid(arg2) to retrieve the connecting process's PID and subsequently passes this value to the hasValidSignature function for code signature verification. This approach fundamentally misunderstands how process identifiers function within operating systems, particularly in scenarios where PIDs can be reused by the system's process scheduler. The PID reuse attack vector exploits the fact that after a process terminates, its PID becomes available for reuse by the kernel, potentially allowing an attacker to impersonate a legitimate process by obtaining a reused PID that matches the expected value.
This vulnerability directly maps to CWE-284, which addresses inadequate access control mechanisms, and specifically relates to improper privilege management through insecure process identification. The attack scenario demonstrates how an adversary can leverage the predictable nature of PID reuse to bypass signature validation checks, effectively allowing unauthorized code execution with elevated privileges. The flaw represents a classic case of trusting unverified identifiers in security-critical contexts, where the assumption that a PID corresponds to a legitimate, authorized process is fundamentally flawed.
The operational impact of this vulnerability extends beyond simple privilege escalation to potentially enable complete system compromise. An attacker who successfully exploits this vulnerability can execute arbitrary code with the privileges of the privileged helper service, which typically operates with elevated permissions. This could result in unauthorized system modifications, data exfiltration, or establishment of persistent backdoors. The attack requires minimal sophistication since it only involves waiting for a PID to be reused and then connecting to the service with that identifier, making it particularly dangerous in environments where the service remains accessible to unprivileged users.
Mitigation strategies must address both the immediate vulnerability and underlying architectural issues. The most effective approach involves replacing PID-based validation with more robust authentication mechanisms such as code signature validation using the actual executable path, Mach port-based identification, or certificate-based authentication. Implementing proper process validation that does not rely on potentially reusable identifiers would eliminate this attack vector entirely. Additionally, systems should employ process lifetime validation, where the service maintains a registry of currently active processes and their valid signatures rather than relying on transient PID values. This approach aligns with ATT&CK technique T1548.002, which addresses privilege escalation through legitimate system tools, by ensuring that only properly authenticated and verified processes can access privileged services. Organizations should also consider implementing additional monitoring and detection mechanisms to identify anomalous XPC service access patterns that might indicate exploitation attempts.