Title

Site isolation for every site must be enabled. (Cat II impact)

Discussion

The "SitePerProcess" policy can be used to prevent users from opting out of the default behavior of isolating all sites. The "IsolateOrigins" policy can be used to isolate additional, finer-grained origins. Enabling this policy prevents users from opting out of the default behavior where each site runs in its own process. If this policy is not disabled or configured, a user can opt out of site isolation (e.g., by using "Disable site isolation" entry in edge://flags.) Disabling the policy or not configuring the policy does not turn off Site Isolation.

Check Content

The policy value for "Computer Configuration/Administrative Templates/Microsoft Edge/Enable site isolation for every site" must be set to "enabled". Use the Windows Registry Editor to navigate to the following key: HKLM\SOFTWARE\Policies\Microsoft\Edge If the value for "SitePerProcess" is not set to "REG_DWORD = 1", this is a finding.

Fix Text

Set the policy value for "Computer Configuration/Administrative Templates/Microsoft Edge/Enable site isolation for every site" to "enabled".

Additional Identifiers

Rule ID: SV-235760r879587_rule

Vulnerability ID: V-235760

Group Title: SRG-APP-000141

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.