Denial of service in HAProxy

1) Infinite loop

EUVDB-ID: #VU96822

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-2024-45506

CWE-ID: CWE-835 - Loop with Unreachable Exit Condition ('Infinite Loop')

Exploit availability: No

Description

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

The vulnerability exists due to infinite loop within the h2_send() function when zero-copy forwarding for HTTP/2 is enabled. A remote attacker can consume all available system resources and cause denial of service conditions.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

HAProxy: 2.9.0 - 3.0.3

CPE2.3

• cpe:2.3:a:haproxy:haproxy:2.9.9:*:*:*:*:*:*:*
• cpe:2.3:a:haproxy:haproxy:3.0.3:*:*:*:*:*:*:*

External links

https://www.haproxy.org/download/3.1/src/CHANGELOG
https://www.mail-archive.com/haproxy%40formilux.org/msg45281.html
https://www.mail-archive.com/haproxy%40formilux.org/msg45280.html
https://git.haproxy.org/?p=haproxy-3.0.git%3Ba=commitdiff%3Bh=c725db17e8416ffb3c1537aea756356228ce5e3c
https://git.haproxy.org/?p=haproxy-3.0.git%3Ba=commitdiff%3Bh=d636e515453320c6e122c313c661a8ac7d387c7f

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.