Firefox must be configured to ask which certificate to present to a website when a certificate is required.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-251547	FFOX-00-000003	SV-251547r807113_rule		Medium

Description
When a website asks for a certificate for user authentication, Firefox must be configured to have the user choose which certificate to present. Websites within DoD require user authentication for access, which increases security for DoD information. Access will be denied to the user if certificate management is not configured.

STIG	Date
Mozilla Firefox Security Technical Implementation Guide	2021-12-01

Details

Check Text ( C-54982r807111_chk )
Type "about:policies" in the browser address bar. If "security.default_personal_cert" is not displayed with a value of "Ask Every Time", this is a finding.

Fix Text (F-54936r807112_fix)
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: Preferences Policy State: Enabled Policy Value: { "security.default_personal_cert": { "Value": "Ask Every Time", "Status": "locked" } } macOS "plist" file: Add the following: Preferences security.default_personal_cert Value Ask Every Time Status locked Linux "policies.json" file: Add the following in the policies section: "Preferences": { "security.default_personal_cert": { "Value": "Ask Every Time", "Status": "locked" } }

Fix Text (F-54936r807112_fix)

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: Preferences
Policy State: Enabled
Policy Value:
{
"security.default_personal_cert": {
"Value": "Ask Every Time",
"Status": "locked"
}
}

macOS "plist" file:
Add the following:
Preferences

security.default_personal_cert

Value
Ask Every Time
Status
locked

Linux "policies.json" file:
Add the following in the policies section:
"Preferences": {
"security.default_personal_cert": {
"Value": "Ask Every Time",
"Status": "locked"
}
}