CVE-2020-2035 PAN-OS: URL filtering policy is not enforced on TLS handshakes for decrypted HTTPS sessions
Attackers can bypass URL filtering on decrypted HTTPS traffic by omitting SNI, allowing compromised hosts to evade security policies.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2020-2035?
CVE-2020-2035 is a low-severity vulnerability in Paloaltonetworks Pan-Os, published on 12 Aug 2020. An attacker needs administrator access to exploit it, with no action from the victim.
Official 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. This issue does not impact Panorama or WF-500 appliances.
Weakness: CWE-20
Which versions are affected by CVE-2020-2035?
It affects 1 product.
Products include Paloaltonetworks Pan-Os.
How do I fix CVE-2020-2035?
No fix has been published for CVE-2020-2035 yet. Limit exposure of the affected software until one is available.
Is CVE-2020-2035 being exploited?
There is no known exploitation of CVE-2020-2035 in the wild and no public exploit code.
Other vulnerabilities in Paloaltonetworks Pan-Os
- CVE-2024-3400 Palo Alto Networks PAN-OS Command Injection
- CVE-2020-2021 Palo Alto Networks PAN-OS Authentication Bypass
- CVE-2017-15944 Palo Alto Networks PAN-OS Remote Code Execution
- CVE-2026-0300 Palo Alto Networks PAN-OS Out-of-bounds Write
- CVE-2024-0012 Palo Alto Networks PAN-OS Management Interface Authentication Bypass
Sources
Also known as GHSA-j3cp-2wgv-xj2j.