#VU25836 Improper access control in envoy - CVE-2020-8660

Vulnerability identifier: #VU25836

Vulnerability risk: High

CVSSv4.0: 8.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2020-8660

CWE-ID: CWE-284

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
envoy
Server applications / IDS/IPS systems, Firewalls and proxy servers

Vendor: Cloud Native Computing Foundation

Description

The vulnerability allows a remote attacker to bypass TLS inspector.

The vulnerability exists due to the TLS extensions (SNI, ALPN) are not inspected, those connections might been matched to a wrong filter chain. A remote attacker can bypass implemented security restrictions in the process and gain unauthorized access to the application.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

envoy: 1.0.0, 1.1.0 - 1.13.0, 1.2.0, 1.3.0, 1.4.0, 1.5.0, 1.6.0, 1.7.0 - 1.7.1, 1.8.0, 1.9.0 - 1.9.1

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External links
https://github.com/envoyproxy/envoy/security/advisories/GHSA-c4g8-7grc-5wvx
https://www.envoyproxy.io/docs/envoy/v1.13.1/intro/version_history

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.