Multiple vulnerabilities in Apache HTTP Server

Published: 2021-12-20 | Updated: 2024-10-25

Risk	Critical
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2021-44790 CVE-2021-44224
CWE-ID	CWE-119 CWE-918
Exploitation vector	Network
Public exploit	Public exploit code for vulnerability #1 is available.
Vulnerable software	Apache HTTP Server Server applications / Web servers
Vendor	Apache Foundation

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Buffer overflow

EUVDB-ID: #VU59056

Risk: Critical

CVSSv4.0: 8.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Red]

CVE-ID: CVE-2021-44790

CWE-ID: CWE-119 - Memory corruption

Exploit availability: Yes

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error when parsing multipart content in mod_lua. A remote attacker can send a specially crafted HTTP request to the affected web server, trigger buffer overflow and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Apache HTTP Server: 2.4 - 2.4.51

CPE2.3

External links

https://downloads.apache.org/httpd/CHANGES_2.4

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. However, proof of concept for this vulnerability is available.

2) Server-Side Request Forgery (SSRF)

EUVDB-ID: #VU59057

Risk: Medium

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:L/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-44224

CWE-ID: CWE-918 - Server-Side Request Forgery (SSRF)

Exploit availability: No

Description

The disclosed vulnerability allows a remote attacker to perform SSRF attacks.

The vulnerability exists due to insufficient validation of user-supplied input in forward proxy configurations. A remote attacker can send a specially crafted HTTP request and trick the web server to initiate requests to arbitrary systems or cause NULL pointer dereference error and crash the web server.

Successful exploitation of this vulnerability may allow a remote attacker gain access to sensitive data, located in the local network or send malicious requests to other servers from the vulnerable system.

SSRF if possible for configuration that mix forward and reverse proxy.