Host HTTP header poisoning in October CMS

1) Inconsistent interpretation of HTTP requests

EUVDB-ID: #VU51380

Risk: Medium

CVSSv3.1: 6.3 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-21265

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

Exploit availability: No

Description

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

The vulnerability exists due to improper validation of HTTP requests. If the server is configured to accept requests with arbitrary HOST header, a remote attacker can send a specially crafted HTTP request to the server and smuggle arbitrary HTTP headers into the request.

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

Mitigation

Install updates from vendor's website and configure the CMS to accept only trusted host names.

Vulnerable software versions

October CMS: 1.0.319 - 1.1.1

External links

http://github.com/octobercms/october/security/advisories/GHSA-xhfx-hgmf-v6vp/

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.