#VU78681 Use-after-free in envoy - CVE-2023-35943

Vulnerability identifier: #VU78681

Vulnerability risk: Medium

CVSSv4.0: 5.4 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N/E:P/U:Green]

CVE-ID: CVE-2023-35943

CWE-ID: CWE-416

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 compromise vulnerable system.

The vulnerability exists due to a use-after-free error in the HTTP CORS filter. A remote user can perform a denial of service (DoS) attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

envoy: 1.23.0 - 1.26.3

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External links
https://github.com/envoyproxy/envoy/security/advisories/GHSA-mc6h-6j9x-v3gq

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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. However, proof of concept for this vulnerability is available.