DISA STIGS Viewer

Firefox deprecated ciphers must be disabled.

Overview

Finding ID Version Rule ID IA Controls Severity
V-251571 FFOX-00-000027 SV-251571r879587_rule   Medium
Description
A weak cipher is defined as an encryption/decryption algorithm that uses a key of insufficient length. Using an insufficient length for a key in an encryption/decryption algorithm opens up the possibility (or probability) that the encryption scheme could be broken.
STIG Date
Mozilla Firefox Security Technical Implementation Guide 2023-06-05

Details

Check Text (C-55006r820760_chk)
Type "about:policies" in the browser address bar.

If "DisabledCiphers" is not displayed under Policy Name or the Policy Value is not "TLS_RSA_WITH_3DES_EDE_CBC_SHA" with a value of "true", this is a finding.
Fix Text (F-54960r820761_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\Disabled Ciphers
Policy Name: TLS_RSA_WITH_3DES_EDE_CBC_SHA
Policy State: Enabled

macOS "plist" file:
Add the following:
<key>DisabledCiphers</key>
<dict>
<key>TLS_RSA_WITH_3DES_EDE_CBC_SHA</key>
<true/>
</dict>

Linux "policies.json" file:
Add the following in the policies section:
"DisabledCiphers": {
"TLS_RSA_WITH_3DES_EDE_CBC_SHA": true
}