Denial of service in HAProxy

1) Input validation error

EUVDB-ID: #VU71431

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 - Improper input validation

Exploit availability: No

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 - 2.7.0

CPE2.3

• cpe:2.3:a:haproxy:haproxy:2.0.30:*:*:*:*:*:*:*
• cpe:2.3:a:haproxy:haproxy:2.1.12:*:*:*:*:*:*:*
• cpe:2.3:a:haproxy:haproxy:2.2.26:*:*:*:*:*:*:*
• cpe:2.3:a:haproxy:haproxy:2.3.21:*:*:*:*:*:*:*
• cpe:2.3:a:haproxy:haproxy:2.4.20:*:*:*:*:*:*:*
• cpe:2.3:a:haproxy:haproxy:2.5.10:*:*:*:*:*:*:*
• cpe:2.3:a:haproxy:haproxy:2.6.7:*:*:*:*:*:*:*
• cpe:2.3:a:haproxy:haproxy:2.7.0:*:*:*:*:*:*:*

External links

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

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

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