IP address spoofing in Apache HTTP Server

1) Input validation error

EUVDB-ID: #VU35776

Risk: Medium

CVSSv3.1: 5.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-11985

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a spoofing attack.

The vulnerability exists due to insufficient validation of user-supplied input. A remote attacker can spoof the user's IP address when proxying using mod_remoteip and mod_rewrite, as a result the fake IP address will be displayed in logs and will be passed to PHP scripts.

Depending on web application functionality this vulnerability can be used to bypass authorization checks based on IP addresses.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Apache HTTP Server: 2.4.1 - 2.4.23

External links

http://httpd.apache.org/security/vulnerabilities_24.html

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.