CVE-2026-4556 in Exam4
Summary
by MITRE • 09/28/2026
Exam4 is affected by a local privilege escalation vulnerability in the com.extegrity.LogTool privileged helper, which communicates with the application via XPC. The [ConsoleLogHelper copyConsoleIntoFileFromStartDate:] method executes a syslog command using attacker-controlled parameters without proper sanitization, enabling command injection. Successful exploitation allows a local attacker to execute arbitrary commands with root privileges through LaunchSynchronous.
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Analysis
by VulDB Data Team • 09/28/2026
Exam4 contains a critical local privilege escalation vulnerability within its com.extegrity.LogTool privileged helper service, which facilitates communication between the application and system-level components via XPC. This architectural design grants the helper process elevated permissions necessary to access sensitive system logs that are otherwise restricted from standard user applications. The core technical flaw resides in the implementation of the [ConsoleLogHelper copyConsoleIntoFileFromStartDate:] method, which is responsible for retrieving console log data based on a specified start date and writing it to a file. This function invokes external shell commands through syslog utilities but fails to properly sanitize or validate the input parameters provided by the calling application before execution.
The lack of proper sanitization creates a classic command injection vulnerability where an attacker who has already achieved local access can manipulate the arguments passed to this method. By supplying specially crafted strings containing malicious shell metacharacters, such as semicolons or pipe operators, within the start date parameter, the attacker can break out of the intended context and inject arbitrary commands into the execution pipeline. Because the helper process operates with root privileges via LaunchSynchronous, any command injected through this vector is executed with the highest level of system authority, effectively bypassing standard user-level security controls.
The operational impact of this vulnerability is severe, as it allows a local attacker to escalate their privileges from an unprivileged user account to full root access on the affected macOS device. This compromise enables the execution of arbitrary code, modification or deletion of critical system files, installation of persistent backdoors, and exfiltration of sensitive data stored within the system logs or other protected directories. The ability to execute commands with root privileges fundamentally undermines the integrity and confidentiality guarantees provided by the operating system's sandboxing mechanisms.
From a classification perspective, this vulnerability aligns closely with CWE-78 Improper Neutralization of Special Elements used in an OS Command commonly known as OS Command Injection. It also relates to CWE-250 Execution with Unnecessary Privileges since the helper process runs at root level for tasks that could potentially be performed with lesser privileges or through safer APIs. In terms of adversary tactics, this exploitation technique maps to ATT&CK T1068 Exploitation for Privilege Escalation and may involve techniques associated with T1059 Command and Scripting Interpreter if the injected commands utilize shell scripting features.
Mitigation strategies should prioritize immediate patching by updating Exam4 to a version that addresses this flaw through rigorous input validation and parameterization of system calls. Developers must avoid passing unsanitized user-controlled data directly into OS command strings and instead use native APIs or library functions that do not invoke the underlying operating system shell whenever possible. If external commands are necessary, strict allow-listing of acceptable characters for parameters like dates should be implemented to ensure only valid date formats are processed. Additionally, applying principle of least privilege by reducing the permissions required by the LogTool helper service can limit the blast radius in case future vulnerabilities are discovered. System administrators should monitor for unusual processes spawned with root privileges and review XPC communication logs for anomalies indicative of exploitation attempts until patches are applied.