#VU71431 Input validation error in HAProxy - CVE-2023-0056

Vulnerability identifier: #VU71431

Vulnerability risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2023-0056

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

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

Vendor: HAProxy

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to insufficient validation of user-supplied input within the http_wait_for_response() function when handling HTTP/2 requests. A remote attacker can send a specially crafted HTTP request the proxy server and perform a denial of service (DoS) attack.

Mitigation
Install update from vendor's website.

Vulnerable software versions

HAProxy: 2.0.0 - 2.0.30, 2.1.0 - 2.1.12, 2.2.0 - 2.2.26, 2.3.0 - 2.3.21, 2.4.0 - 2.4.20, 2.5.1 - 2.5.10, 2.6.0 - 2.6.7, 2.7.0

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External links
https://github.com/haproxy/haproxy/issues/1972

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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.