Title

Firefox development tools must be disabled. (Cat III impact)

Discussion

Information needed by an attacker to begin looking for possible vulnerabilities in a web browser includes any information about the web browser and plug-ins or modules being used. When debugging or trace information is enabled in a production web browser, information about the web browser, such as web browser type, version, patches installed, plug-ins and modules installed, type of code being used by the hosted application, and any back ends being used for data storage may be displayed. Because this information may be placed in logs and general messages during normal operation of the web browser, an attacker does not have to cause an error condition to gain this information.

Check Content

Type "about:policies" in the browser window. If "DisableDeveloperTools" is not displayed under Policy Name or the Policy Value is not "true", this is a finding.

Fix Text

Windows group policy: 1. Open the group policy editor tool with "gpedit.msc". 2. Navigate to Policy Path: Computer Configuration\Administrative Templates\Mozilla\Firefox Policy Name: Disable Developer Tools Policy State: Enabled macOS "plist" file: Add the following: <key>DisableDeveloperTools</key> <true/> Linux "policies.json" file: Add the following in the policies section: "DisableDeveloperTools": true

Additional Identifiers

Rule ID: SV-251559r879655_rule

Vulnerability ID: V-251559

Group Title: SRG-APP-000266

Expert Comments

CCIs tied to check.

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