Decryption profile permits an invalid server certificate
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
These settings decide what the firewall does when the server it decrypts presents a certificate that is expired, issued by an issuer the device does not trust, or otherwise unknown. Set to no, the configuration permits the session to continue, which is the case a decrypting firewall is best placed to catch.
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.
- Set the forward proxy checks named above to yes.
- Import the internal issuing certificate authority on the device first, or internal sites signed privately will be blocked.
- The equivalent settings under the no-decrypt half of the profile cover traffic the profile does not decrypt.
Command line
PAN-OS CLI, standalone firewall, vsys1
set vsys vsys1 profiles decryption <profile> ssl-forward-proxy block-expired-certificate yesset vsys vsys1 profiles decryption <profile> ssl-forward-proxy block-untrusted-issuer yesset vsys vsys1 profiles decryption <profile> ssl-forward-proxy block-unknown-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 <profile> ssl-forward-proxyValues to fill in1
- <profile>
- Which profile to change. A firewall carries several of each kind.
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 SSL forward proxy settings and confirm each check.
- Browse to a site with a deliberately expired certificate and confirm the block page appears.
Limits
- Whether this profile is attached to a gateway or a tunnel is a separate question. A profile defined and never referenced carries no exposure.
- Only settings written as no are reported. A check the file does not state is not a check that was turned off.
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-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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