MacVims configuration on macOS, specifically the presence of entitlement com.apple.security.get-task-allow, allows local attackers with unprivileged access (e.g. via a malicious application) to attach a debugger, read or modify the process memory, inject code in the applications context despite being signed with Hardened Runtime and bypass Transparency, Consent, and Control (TCC). Acquired resource access is limited to previously granted permissions by the user. Access to other resources beyond granted permissions requires user interaction with a system prompt asking for permission.
According to Apple documentation, when a non-root user runs an app with the debugging tool entitlement, the system presents an authorization dialog asking for a system administrators credentials. Since there is no prompt when the target process has get-task-allow entitlement, the presence of this entitlement was decided to be treated as a vulnerability because it removes one step needed to perform an attack.
This issue was fixed in build r181.2
The product does not properly prevent sensitive system-level information from being accessed by unauthorized actors who do not have the same level of access to the underlying system as the product does.
Network-based products, such as web applications, often run on top of an operating system or similar environment. When the product communicates with outside parties, details about the underlying system are expected to remain hidden, such as path names for data files, other OS users, installed packages, the application environment, etc. This system information may be provided by the product itself, or buried within diagnostic or debugging messages. Debugging information helps an adversary learn about the system and form an attack plan. An information exposure occurs when system data or debugging information leaves the program through an output stream or logging function that makes it accessible to unauthorized parties. Using other weaknesses, an attacker could cause errors to occur; the response to these errors can reveal detailed system information, along with other impacts. An attacker can use messages that reveal technologies, operating systems, and product versions to tune the attack against known vulnerabilities in these technologies. A product may use diagnostic methods that provide significant implementation details such as stack traces as part of its error handling mechanism.