ProxySG ICAP policy fail_open overrules ICAP policy to block and serve the file
Article ID: 169182
Updated On:
Products
Issue/Introduction
This is expected behavior.
Cause
The ProxySG policy of response.icap_service(virus_scan, fail_open) is designed to fail-open to any errors whether they are health-check related or an error is returned from the ICAP service. Thus, if the ICAP policy is set to block a file extension the ICAP service will return a 500 server error code, as per RFC3507, in which case the SG receives the error and fails-open as per policy.
Resolution
To implement policy for handling of particular icap error codes in fail-open environments, follow the guidance below:
These policy definitions can be found in the respective CPL and VPM guides for the ProxySG, heading icap_error_code.
SGOS 7.3:
CPL Guide on page 245
VPM Guide on page 131
SGOS 7.2:
CPL Guide on page 238
VPM Guide on page 131
SGOS 7.1:
CPL Guide on page 217
VPM Guide on page 133
SGOS 6.7:
CPL Guide on page 195
VPM Guide on page 129
SGOS 6.5:
CPL Guide on page 145
VPM Guide on page 118
The icap_error_code option triggers on the X-ICAP-Error header, instead of relying on the response code.
Workaround
None.
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