CVE-2020-2035 Detail

Current Description

When SSL/TLS Forward Proxy Decryption mode has been configured to decrypt the web transactions, the PAN-OS URL filtering feature inspects the HTTP Host and URL path headers for policy enforcement on the decrypted HTTPS web transactions but does not consider Server Name Indication (SNI) field within the TLS Client Hello handshake. This allows a compromised host in a protected network to evade any security policy that uses URL filtering on a firewall configured with SSL Decryption in the Forward Proxy mode. A malicious actor can then use this technique to evade detection of communication on the TLS handshake phase between a compromised host and a remote malicious server. This technique does not increase the risk of a host being compromised in the network. It does not impact the confidentiality or availability of a firewall. This is considered to have a low impact on the integrity of the firewall because the firewall fails to enforce a policy on certain traffic that should have been blocked. This issue does not impact the URL filtering policy enforcement on clear text or encrypted web transactions. This technique can be used only after a malicious actor has compromised a host in the protected network and the TLS/SSL Decryption feature is enabled for the traffic that the attacker controls. Palo Alto Networks is not aware of any malware that uses this technique to exfiltrate data. This issue is applicable to all current versions of PAN-OS.


View Analysis Description

Severity



CVSS 3.x Severity and Metrics:

NIST CVSS score matches with CNA score
CNA:  Palo Alto Networks, Inc.
Base Score:  3.0 LOW
Vector:  CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:N/I:L/A:N


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Hyperlink Resource
https://security.paloaltonetworks.com/CVE-2020-2035 Vendor Advisory 
https://www.mnemonic.no/blog/introducing-snicat/ Third Party Advisory 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-20 Improper Input Validation cwe source acceptance level NIST   Contributor acceptance level Palo Alto Networks, Inc.  

Known Affected Software Configurations Switch to CPE 2.2

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Change History

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Quick Info

CVE Dictionary Entry:
CVE-2020-2035
NVD Published Date:
08/12/2020
NVD Last Modified:
08/19/2020
Source:
Palo Alto Networks, Inc.