Vulnerability identifier: #VU53524

Vulnerability risk: High

CVSSv3.1: 7.1 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-31920

CWE-ID: CWE-285

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Istio
Web applications / Other software

Vendor: Istio

Description

The vulnerability allows a remote attacker to bypass authorization checks.

The vulnerability exists due to improper input validation when processing HTTP request path with multiple slashes or escaped slash characters (%2F or %5C). A remote attacker can bypass Istio authorization policy when path based authorization rules are used.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Istio: 0.1 - 1.10.0

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External links
http://istio.io/latest/news/security/istio-security-2021-005/

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

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