Headline
CVE-2021-32692: Shell execution on macOS from arbitrary websites through printAppTitle.scpt
Activity Watch is a free and open-source automated time tracker. Versions prior to 0.11.0 allow an attacker to execute arbitrary commands on any macOS machine with ActivityWatch running. The attacker can exploit this vulnerability by having the user visiting a website with the page title set to a malicious string. An attacker could use another application to accomplish the same, but the web browser is the most likely attack vector. This issue is patched in version 0.11.0. As a workaround, users can run the latest version of aw-watcher-window from source, or manually patch the printAppTitle.scpt file.
Impact
Allows an attacker to execute arbitrary commands on any macOS machine with ActivityWatch running, if they can get the user to open an application (like a web browser) such that it sets the application’s window title to a malicious string.
The attacker can exploit this vulnerability by having the user visiting a website with the page title set to a malicious string. An attacker could use another application to accomplish the same, but the web browser is the most likely attack vector.
Patches
A pull request (ActivityWatch/aw-watcher-window#52) has been merged which changes the default method of fetching the window title, and this new method is unaffected. The previous method is still available through configuration, and has also been patched (ActivityWatch/aw-watcher-window#56).
Users should update to v0.11.0 as soon as possible.
Workarounds
Run the latest version of aw-watcher-window from source, or manually patch the printAppTitle.scpt file.
Credit
This vulnerability was discovered by Janne Uusitupa (@lambdanana), and fixes were contributed by Erik Bjäreholt (@ErikBjare).