HTTP request smuggling in HAProxy

1) Inconsistent interpretation of HTTP requests

EUVDB-ID: #VU72334

Risk: Medium

CVSSv3.1: 5.3 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2023-25725

CWE-ID: CWE-444 - Inconsistent Interpretation of HTTP Requests ('HTTP Request Smuggling')

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform HTTP request smuggling attacks.

The vulnerability exists due to improper validation of HTTP/1 requests. A remote attacker can send a specially crafted HTTP request with empty fields, which could be used to truncate the list of HTTP headers and thus make some headers disappear after being parsed and processed for HTTP/1.0 and HTTP/1.1

Successful exploitation of vulnerability may allow an attacker to poison HTTP cache and perform phishing attacks.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

HAProxy: 2.0.0 - 2.7.2

External links

http://git.haproxy.org/?p=haproxy-2.7.git;a=commit;h=a0e561ad7f29ed50c473f5a9da664267b60d1112
http://lists.debian.org/debian-lts-announce/2023/02/msg00012.html
http://www.debian.org/security/2023/dsa-5348

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.