HTTP request smuggling in mitmproxy

1) Inconsistent interpretation of HTTP requests

EUVDB-ID: #VU56667

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-2021-39214

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. A remote attacker can send a specially crafted HTTP request to the proxy server and smuggle arbitrary HTTP headers.

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

The vulnerability can be exploited by both, a malicious server and client.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

mitmproxy: 0.1 - 7.0.2

External links

http://github.com/mitmproxy/mitmproxy/security/advisories/GHSA-22gh-3r9q-xf38

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.