Activity Watch vulnerable to command execution on macOS via printAppTitle.scpt

Vulnerability

Activity Watch versions prior to 0.11.0 contain a code injection vulnerability in the macOS-specific printAppTitle.scpt script, which is responsible for retrieving the active application window's title. By setting the window title to a specially crafted string (e.g., via a web page title or other application), an attacker can inject arbitrary AppleScript commands that the script executes without sanitization. The attack is most easily triggered when a user visits a website whose page title contains the malicious payload, but any application that sets an attacker-controlled window title could be used. [1]

Exploitation

An attacker must lure a user running an affected Activity Watch version (prior to 0.11.0) on macOS into opening an application that sets its window title to a malicious string. The most likely vector is a web browser: the attacker hosts a page whose HTML ` (or equivalent) contains the crafted payload, and convinces the user to navigate to it. The aw-watcher-window process periodically calls printAppTitle.scpt` to read the foreground window's title; the script does not escape or validate the input, allowing the injected AppleScript code to execute with the privileges of the user. No authentication or prior access to the target machine is required beyond the user performing the action. [1]

Impact

Successful exploitation achieves arbitrary command execution on the victim's macOS machine. The attacker can run shell commands or AppleScript instructions, leading to full compromise of user data, installation of malware, credential theft, or any action the user can perform on the system. The impact is limited to machines running ActivityWatch on macOS; the code runs in the context of the logged-in user. [1]

Mitigation

The issue is fixed in Activity Watch version 0.11.0, released according to the advisory. Users should update immediately. As a workaround, users can run the latest version of aw-watcher-window from source or manually apply the patched version of the printAppTitle.scpt file. No other mitigations are provided in the references. [1]