Server-Side Request Forgery (SSRF) in Apache HTTP Server - CVE-2021-40438
Published: September 17, 2021 / Updated: December 18, 2023
Vulnerability identifier: #VU56678
CSH Severity: High
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:L/SI:N/SA:N/E:A/U:Amber
CVE-ID: CVE-2021-40438
CWE-ID: CWE-918
Exploitation vector: Remote access
Exploit availability:
The vulnerability is being exploited in the wild
Vendor: Apache Foundation
Affected software:
Apache HTTP Server
Apache HTTP Server
Detailed vulnerability description
The disclosed vulnerability allows a remote attacker to perform SSRF attacks.
The vulnerability exists due to insufficient validation of user-supplied input within the mod_proxy module in Apache HTTP Server. A remote attacker can send a specially crafted HTTP request with a chosen uri-path and trick the web server to initiate requests to arbitrary systems.
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.
How to mitigate CVE-2021-40438
Install updates from vendor's website.