#VU25386 Improper Authentication in Istio - CVE-2020-8843

Vulnerability identifier: #VU25386

Vulnerability risk: Medium

CVSSv4.0: 6.9 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2020-8843

CWE-ID: CWE-287

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Istio
Web applications / Other software

Vendor: Istio

Description

The vulnerability allows a remote attacker to bypass authentication process.

The vulnerability exists due to an error in Mixer policy checks. Istio-proxy accepts x-istio-attributes header at ingress that can be used to affect policy decisions when Mixer policy selectively applies to source equal to ingress. A remote attacker can bypass authentication process and gain unauthorized access to the application.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Istio: 1.3 - 1.3.6

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External links
https://github.com/istio/istio/commits/master
https://istio.io/news/security/
https://istio.io/news/security/istio-security-2020-002/

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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.