Unable to set CAS "out of temporary storage space" to "serve"

Products

• ISG Content Analysis

Issue/Introduction

Content Analysis Server (CAS) admin upgraded CAS VA from CAS 3.2.2.1 to version 4.1.2.1.

When CAS admin setting up to serve the option 'out of temporary storage space' in Policies for Anti-virus exceptions as shown below, the setting always jumps back to default 'block' after saving and refreshing the page.

Running the same configuration change on a test CAS 3.2.2.1 server showed the setting persisted.

Environment

CAS 4.1.2.1.

Admin Console.

Cause

Defect.

Resolution

The UI defect will be fixed in next planned CAS update (4.1.3.1).

If your organization specifically requires that files bypass scanning when the CAS storage buffer is full, you can override the GUI block using the Command Line Interface (CLI) instead as a workaround. The configuration parameter you need to toggle is block-storage-error.

1. Establish an SSH session to your CAS appliance.

2. Enter Privileged mode, then Global Configuration mode:

   CAS> enable
   CAS# configure terminal
   

3. Enter the services policy configuration context:

   CAS(config)# services policy
   

4. Turn off the forced block on storage errors (this acts as setting the policy to "Serve"):

   CAS(config-policy)# block-storage-error false
   

5. Save your configuration.

Additional Information

Grabbing the HAR file from the working and non working scenario helped identify the issue:

Accessing the CAS 3.2 appliance with developer tools enabled and pushing the change via the UI, the Storage_Policy setting handling the out of storage space response is part of the POST payload:

When trying to do the same operation on 4.1.2.1 via the UI, the POSTing of the uploaded config does not include the Storage_Policy parameter setting ie. that information is never sent to the back end, when all the other options are.

The 4.1.3.1 upgrade will resent this Storage_Policy setting.