Decryption profile lets undecryptable forward proxy sessions through
At a glance
Base severity
Area
Platform
Evidence level
Benchmark reference
Reads the export, not the device
ConfigProof reads a configuration export. This control is evaluated against the objects in that file, and it reports what the file says. It does not connect to the device and sees no traffic, so a finding here describes the configuration, not what the firewall is doing right now.
Why it matters
A session the firewall cannot decrypt, because of an unsupported version or cipher or a certificate status check that timed out, passes uninspected when these are not blocked. An attacker who can choose the handshake can choose to be one of them.
How to fix it
Web interface
The steps below are written for the web interface. A finding raised on your own export carries the same steps with your object names filled in.
- Enable block-unsupported-version, block-unsupported-cipher and block-timeout-cert under the profile's SSL forward proxy settings.
- Add a no-decrypt rule for any site that legitimately needs one of these, rather than leaving the whole profile open.
Command line
PAN-OS CLI, standalone firewall, vsys1
set vsys vsys1 profiles decryption <object-name> ssl-forward-proxy block-unsupported-version yesset vsys vsys1 profiles decryption <object-name> ssl-forward-proxy block-unsupported-cipher yesset vsys vsys1 profiles decryption <object-name> ssl-forward-proxy block-timeout-cert yes
An example. Values in angle brackets are yours to supply; a finding on your own export fills in the names it read. Nothing here commits. Review the candidate configuration, then commit it yourself.
Read it back
show vsys vsys1 profiles decryption <object-name> ssl-forward-proxyValues to fill in1
- <object-name>
- The object's name, as it appears on your firewall
Before you type it1
- Sites with a certificate problem stop loading rather than warning. Expect a first day of reports.
How to confirm the fix
- Reopen the profile's forward proxy settings and confirm each block.
- Watch the decryption log for sessions blocked by these settings for a day.
Limits
- A setting the profile does not write inherits a PAN-OS default this file does not record; the check reports it as not written, not as permitted.
Compliance references
No benchmark recommendation is mapped to this control in this version.
More in Decryption
- PAN-SEC-014No decryption policy covering outbound traffic
- PAN-SEC-089Decryption profile permits a TLS version with published breaks
- PAN-SEC-090Decryption profile permits an invalid server certificate
- PAN-SEC-091Decryption rule excludes a high-risk URL category from decryption
- PAN-SEC-106Decryption profile permits a legacy cipher, hash or key exchange
- PAN-SEC-134Decrypted content is not forwarded to WildFire
See it on your own firewall
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