Explain the calculation to determine the risk score for the applications.
Environment
All PAN-OS All PAN products that used Applications
Resolution
Shown below is the matrix used to determine the risk level of threats, spyware, and anti-virus.
Technology
Technology
Description
network-protocol
An application that is generally used for system to system communication that facilitates network operation. This includes most of the IP protocols.
client-server
An application that uses a client-server model where one or more clients communicate with a server in the network.
peer-to-peer
An application that communicates directly with other clients to transfer information instead of relying on a central server to facilitate the communication.
browser-based
An application that relies on a web browser to function.
Characteristics
Characteristic
Description
Capable of File Transfer
Likely has more than 1,000,000 users. Has the capability to transfer a file from one system to another over a network. A streaming app that has no other mechanism to transfer files other than the video or audio streaming should not be flagged as able to transfer files.
Used by Malware
Malware has been known to use the app for propagation, attack, or data theft, or is distributed with malware.
Excessive Bandwidth Use
Consumes at least 1 Mbps on a regular basis through normal use.
Evasive
Uses a port or protocol for something other than its originally intended purpose with the hope that it will traverse a firewall.
Pervasive
Likely has more than 1,000,000 users.
Known Vulnerabilities
Has publicly reported vulnerability. For web-based apps, it should also be set to yes, as HTTP always has vulnerability.
Prone to Misuse
Often used for nefarious purposes or is easily setup to expose more than the user intended.
Tunnels Other Apps
Is able to transport other applications inside its protocol.
File-type ident
Should be set if app can upload or download a file-type over a decodable protocol (e.g. http).
Spyware-ident
Should be set if the app can upload or download an executable file over a decodable protocol.
Virus-ident
Same as spyware ident.
Vulnerability-ident
For web-based apps, the vulnerability-ident should always be yes, since they are http and http always has some vulnerabilities.
deny-action
For web-based apps,deny-action should be set to drop-reset (unless there is some issues with the app receiving tcp-reset).
Risk Calculation
Weights
Characteristic
Factor
Evasive
3
Excessive Bandwidth Use
1
Used by Malware
4
Capable of File Transfer
3
Known Vulnerabilities
3
Tunnels Other Apps
2
Prone to Misuse
2
Pervasive
1
Total
19
Risk Assignment
Risk
Range
1
0–3
2
4–6
3
7–9
4
10–13
5
14+
Additional Information
Many applications have such characteristics; however, SaaS characteristic does not impact the risk score.
This article covers the criteria of the Palo Alto Networks to categorize threat severity.