Apple Safari
TMA-SAFARI-1.1
Ensure 'Open "safe" files after downloading' is 'Disabled'
Description
The Safari browser contains a feature which causes all files considered "safe" to be automatically opened once they have finished downloading. Rationale: This feature is meant to be a benefit but having the browser automatically open files that could be malicious and downloaded by mistake is a security risk. Audit reads AutoOpenSafeDownloads from the com.apple.Safari preference domain of the account running the scan (the PDF checks the same token in com.apple.Safari.plist; manual check: Follow the below steps and verify that Open "safe" files after downloading is Disabled: 1. Click Safari. 2. Click Preferences. 3. Click General. 4. Verify Open "safe" files after downloading is unchec). Safari is sandboxed, so the reading process needs Full Disk Access on macOS 10.14+. A missing key exits non-zero and is reported as FAIL even where the built-in default is compliant. Values forced by a configuration profile live in /Library/Managed Preferences and are not read here.
How it is checked
Audit method: Shell command
out=$(defaults read com.apple.Safari AutoOpenSafeDownloads 2>/dev/null) || exit 1; printf '%s\n' "$out"- Expected output
0
How it is fixed
Fix method: Guidance or infrastructure patch
Follow the below steps to set Open "safe" files after downloading to Disabled: 1. Click Safari. 2. Click Preferences. 3. Click General. 4. Uncheck the Open "safe" files after downloading checkbox. Or deploy a configuration profile for com.apple.Safari setting AutoOpenSafeDownloads = false, or as the logged-in user run: defaults write com.apple.Safari AutoOpenSafeDownloads -bool false and restart Safari.
Properties
- Operating systems
- Any
- Tags
- safaribrowsercis-l1
- Reference
- CIS macOS Safari Benchmark v2.0.0 - 1.1 Ensure 'Open "safe" files after downloading' is 'Disabled'
Check this host
Run this on a machine you are allowed to audit. The scan is read-only.
tmaegis scan --target safari