Apple iOS/iPadOS 26 must disable app installation from a website.

STIG ID: AIOS-26-015000  |  SRG: PP-MDF-993300 |  Severity: medium (CAT II)  |  CCI: CCI-000366 |  Vulnerability Id: V-278825

Vulnerability Discussion

Forcing all applications to be installed from authorized application repositories can prevent unauthorized and malicious applications from being installed and executed on mobile devices. Allowing such installations and executions could cause a compromise of DOD data accessible by these unauthorized/malicious applications.

SFR ID: FMT_MOF_EXT.1.2 #47

Check

This check procedure is performed on both the device management tool and the iPhone and iPad.

Note: If an organization has multiple configuration profiles, the check procedure must be performed on the relevant configuration profiles applicable to the scope of the review.

In the iOS management tool, verify "Allow app installation from website" is unchecked.

On the iPhone and iPad device:
1. Open the Settings app.
2. Tap "General".
3. Tap "VPN & Device Management".
4. Tap the Configuration Profile from the iOS management tool containing the restrictions policy.
5. Tap "Restrictions".
6. Verify "Web app distribution not allowed" is listed.

If "Allow app installation from website" is not disabled in the management tool or on the Apple device "Web app distribution not allowed" is not listed, this is a finding.

Fix

Install a configuration profile to disable app installation from a website.

Configuration Profile Key: allowWebDistributionAppInstallation