No decryption policy covering outbound traffic
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
Threat prevention cannot inspect what it cannot read. With no decryption rule covering outbound sessions, most of the security profiles attached to outbound rules only see the TLS handshake.
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.
- Build a decryption policy for outbound sessions with an exclusion list for finance, health and privacy categories.
- Roll it out to a pilot user group first and watch for application breakage.
- Document the exclusions so the gap is a decision, not an accident.
Command line
PAN-OS CLI, standalone firewall, vsys1
set vsys vsys1 rulebase decryption rules <decryption-rule-name> from <internal-zone>set vsys vsys1 rulebase decryption rules <decryption-rule-name> to <external-zone>set vsys vsys1 rulebase decryption rules <decryption-rule-name> source anyset vsys vsys1 rulebase decryption rules <decryption-rule-name> destination anyset vsys vsys1 rulebase decryption rules <decryption-rule-name> category <categories-to-decrypt>set vsys vsys1 rulebase decryption rules <decryption-rule-name> action decryptset vsys vsys1 rulebase decryption rules <decryption-rule-name> type ssl-forward-proxy
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 rulebase decryption rules <decryption-rule-name>Values to fill in4
- <decryption-rule-name>
- A name for the new decryption rule
- <internal-zone>
- The zone on the inside
- <external-zone>
- The zone facing the internet
- <categories-to-decrypt>
- The URL categories to decrypt
Before you type it2
- Forward proxy needs a certificate the clients already trust.
- Add the exclusions your applications need before you turn decryption on.
How to confirm the fix
- Confirm no upstream device is already performing decryption for these flows.
- Pilot the decryption policy with one user group and watch for application breakage.
Limits
- Decryption may be handled by a separate device, or be legally restricted in some jurisdictions. Confidence is 0.6 and this is reported as a gap to confirm, not a proven fault.
Compliance references
CIS Palo Alto Firewall 11 Benchmark v1.2.0
Covers part of the recommendation
Where a control aligns with a recommendation of the CIS Palo Alto Firewall 11 Benchmark v1.2.0, that recommendation is cited as a reference. Only that version was checked. A reference is not a certification.
More in Decryption
- 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-107Decryption profile lets undecryptable forward proxy sessions through
- PAN-SEC-134Decrypted content is not forwarded to WildFire
See it on your own firewall
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