Vulnerability identifier: #VU74474

Vulnerability risk: Medium

CVSSv3.1: 4.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2023-27488

CWE-ID: CWE-20

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 escalate privileges on the system.

The vulnerability exists due to insufficient validation of user-supplied input when "failure_mode_allow: true" is configured for ext_authz filter. A remote attacker can pass specially crafted input to the application and gain elevated privileges on the target system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

envoy: 1.0.0 - 1.25.3

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External links
http://github.com/envoyproxy/envoy/security/advisories/GHSA-9g5w-hqr3-w2ph
http://github.com/envoyproxy/envoy/releases/tag/v1.25.4
http://github.com/envoyproxy/envoy/releases/tag/v1.24.5
http://github.com/envoyproxy/envoy/releases/tag/v1.23.7
http://github.com/envoyproxy/envoy/releases/tag/v1.22.10

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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.