Server-Side Request Forgery (SSRF) in Apache HTTP Server - CVE-2021-40438

Vulnerability identifier: #VU56678

CSH Severity: High

CVSS v4: 8.8 [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]

CVE-ID: CVE-2021-40438

CWE-ID: CWE-918

Exploitation vector: Remote access

Exploit availability: The vulnerability is being exploited in the wild

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.

Apache HTTP Server
IBM HTTP Server
Gentoo Linux
Amazon Linux AMI
F5OS
SUSE CaaS Platform
SUSE Enterprise Storage
Red Hat Enterprise Linux Server
CentOS
Red Hat Enterprise Linux Workstation
Red Hat Enterprise Linux Desktop
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for Power, big endian
Red Hat Enterprise Linux for Scientific Computing
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux Server - AUS
Red Hat Enterprise Linux Server - TUS
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for ARM 64
Anolis OS
OpenStack Cloud Crowbar
SUSE OpenStack Cloud
Red Hat Enterprise Linux for ARM 64 - Extended Update Support
Red Hat Enterprise Linux for Power, little endian - Extended Update Support
Red Hat Enterprise Linux for IBM z Systems - Extended Update Support
Red Hat Enterprise Linux for x86_64 - Extended Update Support
SUSE Linux Enterprise Server
Slackware Linux
Ubuntu
SUSE Linux Enterprise Server for SAP
SUSE Linux Enterprise High Performance Computing
SUSE Linux Enterprise Module for Server Applications
SUSE Linux Enterprise Module for Basesystem
openEuler
Fedora
SINEC NMS
Oracle Enterprise Manager Ops Center
IBM DS8000 Hardware Management Console
Cisco Security Manager
IBM Security SiteProtector System
Cisco Expressway
TelePresence Video Communication Server (VCS)
Watson Studio on Cloud Pak for Data
XtremIO X2
Maximo Application Suite - IoT Component
Red Hat Software Collections
jbcs-httpd24-mod_http2 (Red Hat package)
jbcs-httpd24-mod_md (Red Hat package)
apache2 (Debian package)
httpd24-httpd (Red Hat package)
jbcs-httpd24-httpd (Red Hat package)
jbcs-httpd24-mod_security (Red Hat package)
Red Hat Enterprise Linux Server for x86_64 - Update Services for SAP Solutions
Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions
SUSE Linux Enterprise Module for Packagehub Subpackages
mod_http2
mod_md
httpd (Red Hat package)
apache2 (Ubuntu package)
apache2-bin (Ubuntu package)
apache2-doc
apache2-worker-debuginfo
apache2-worker
apache2
apache2-debuginfo
apache2-debugsource
apache2-devel
apache2-prefork
apache2-prefork-debuginfo
apache2-utils
apache2-utils-debuginfo
httpd-filesystem
mod_ldap
httpd-manual
httpd
httpd-devel
httpd-tools
mod_ssl
mod_session
mod_proxy_html
apache2-event-debuginfo
apache2-event
httpd-debuginfo
httpd-debugsource
httpd-help
www-servers/apache
app-admin/apache-tools
JBoss Core Services
EasyApache
Dell Secure Connect Gateway
Oracle HTTP Server
SINEMA Server
IBM Aspera Orchestrator
Oracle Secure Global Desktop
Tenable.sc
Zimbra Collaboration
IBM Aspera Faspex for Linux
IBM Aspera Faspex for Windows
Dell EMC Unity VSA Operating Environment (OE)
Dell EMC Unity XT Operating Environment (OE)
Dell EMC Unity Operating Environment (OE)

Install updates from vendor's website.

Apache HTTP Server - update to 2.4.49
Cisco Expressway - addressed in versions X14.0.4, X14.1, X14.2
TelePresence Video Communication Server (VCS) - addressed in versions X14.0.4, X14.1, X14.2
jbcs-httpd24-mod_http2 (Red Hat package) - addressed in versions 1.15.7-19.el8jbcs, 1.15.7-19.jbcs.el7
jbcs-httpd24-mod_md (Red Hat package) - addressed in versions 2.0.8-38.el8jbcs, 2.0.8-38.jbcs.el7
apache2 (Debian package) - addressed in versions 2.4.38-3+deb10u6, 2.4.51-1~deb11u1
httpd24-httpd (Red Hat package) - update to 2.4.34-23.el7.5
JBoss Core Services - update to 2.4.37 SP9
jbcs-httpd24-httpd (Red Hat package) - addressed in versions 2.4.37-76.el8jbcs, 2.4.37-76.jbcs.el7
jbcs-httpd24-mod_security (Red Hat package) - addressed in versions 2.9.2-65.GA.el8jbcs, 2.9.2-65.GA.jbcs.el7
IBM Security SiteProtector System - update to 3.1.1.17
EasyApache - update to 4 2021-9-22
Dell Secure Connect Gateway - update to 5.12.00.10
Tenable.sc - update to Patch 202110.1
Zimbra Collaboration - addressed in versions 8.8.15 Patch 31, 9.0.0 Patch 24
mod_http2 - update to 1.15.7-3
mod_md - update to 2.0.8-8
httpd (Red Hat package) - addressed in versions 2.4.6-40.el7_2.7, 2.4.6-45.el7_3.6, 2.4.6-67.el7_4.7, 2.4.6-89.el7_6.2, 2.4.6-90.el7_7.1, 2.4.6-97.el7_9.1
apache2 (Ubuntu package) - addressed in versions 2.4.29-1ubuntu4.17, 2.4.29-1ubuntu4.18, 2.4.41-4ubuntu3.5, 2.4.41-4ubuntu3.6, 2.4.46-4ubuntu1.2, 2.4.46-4ubuntu1.3, 2.4.182ubuntu3.17+esm2, 2.4.182ubuntu3.17+esm3
apache2-bin (Ubuntu package) - addressed in versions 2.4.29-1ubuntu4.17, 2.4.29-1ubuntu4.18, 2.4.41-4ubuntu3.5, 2.4.41-4ubuntu3.6, 2.4.46-4ubuntu1.2, 2.4.46-4ubuntu1.3, 2.4.182ubuntu3.17+esm2, 2.4.182ubuntu3.17+esm3
apache2-doc - addressed in versions 2.4.33-3.55.1, 2.4.43-3.32.1
apache2-worker-debuginfo - addressed in versions 2.4.33-3.55.1, 2.4.43-3.32.1
apache2-worker - addressed in versions 2.4.33-3.55.1, 2.4.43-3.32.1
apache2 - addressed in versions 2.4.33-3.55.1, 2.4.43-3.32.1
apache2-debuginfo - addressed in versions 2.4.33-3.55.1, 2.4.43-3.32.1
apache2-debugsource - addressed in versions 2.4.33-3.55.1, 2.4.43-3.32.1
apache2-devel - addressed in versions 2.4.33-3.55.1, 2.4.43-3.32.1
apache2-prefork - addressed in versions 2.4.33-3.55.1, 2.4.43-3.32.1
apache2-prefork-debuginfo - addressed in versions 2.4.33-3.55.1, 2.4.43-3.32.1
apache2-utils - addressed in versions 2.4.33-3.55.1, 2.4.43-3.32.1
apache2-utils-debuginfo - addressed in versions 2.4.33-3.55.1, 2.4.43-3.32.1
httpd-filesystem - update to 2.4.37-43.0.1
mod_ldap - update to 2.4.37-43.0.1
httpd-manual - update to 2.4.37-43.0.1
httpd - update to 2.4.37-43.0.1
httpd-devel - update to 2.4.37-43.0.1
httpd-tools - update to 2.4.37-43.0.1
mod_ssl - update to 2.4.37-43.0.1
mod_session - update to 2.4.37-43.0.1
mod_proxy_html - update to 2.4.37-43.0.1
apache2-event-debuginfo - update to 2.4.43-3.32.1
apache2-event - update to 2.4.43-3.32.1
httpd-debuginfo - update to 2.4.43-9
mod_md - update to 2.4.43-9
mod_ssl - update to 2.4.43-9
httpd - update to 2.4.43-9
httpd-filesystem - update to 2.4.43-9
httpd-devel - update to 2.4.43-9
httpd-tools - update to 2.4.43-9
mod_ldap - update to 2.4.43-9
mod_proxy_html - update to 2.4.43-9
httpd-debugsource - update to 2.4.43-9
mod_session - update to 2.4.43-9
httpd-help - update to 2.4.43-9
httpd - addressed in versions 2.4.49-1.fc34, 2.4.49-1.fc35
www-servers/apache - update to 2.4.54
app-admin/apache-tools - update to 2.4.54
IBM Aspera Orchestrator - update to 4.0.1.2b9681
IBM Aspera Faspex for Linux - update to 4.4.2
IBM Aspera Faspex for Windows - update to 4.4.2
Watson Studio on Cloud Pak for Data - addressed in versions 4.8.7, 5.1.0
Dell EMC Unity VSA Operating Environment (OE) - update to 5.2.0.0.5.173
Dell EMC Unity XT Operating Environment (OE) - update to 5.2.0.0.5.173
Dell EMC Unity Operating Environment (OE) - update to 5.2.0.0.5.173
XtremIO X2 - update to 6.4.2-13
Maximo Application Suite - IoT Component - addressed in versions 8.7.20, 8.8.16, 9.0.6
IBM HTTP Server - update to 9.0.5.10
IBM DS8000 Hardware Management Console - update to 89.30.68.0

• Exploit #9437 - CVE-2021-40438-Apache-2.4.48-SSRF-exploit (CVE-2021-40438 Apache <= 2.4.48 SSRF exploit) (December 18, 2023)
• Exploit #8220 - CVE-2021-40438 (Apache forward request CVE) (August 7, 2022)
• Exploit #7023 - apache-cve-poc (Dockerized Proof-of-Concept of CVE-2021-40438 in Apache 2.4.48.) (November 16, 2021)
• Exploit #6928 - CVE-2021-40438 (CVE-2021-40438 exploit PoC with Docker setup.) (October 24, 2021)
• Exploit #6907 - CVE-2021-40438 () (October 18, 2021)

• https://httpd.apache.org/security/vulnerabilities_24.html

• Multiple vulnerabilities in Apache HTTP Server
• Slackware Linux update for httpd
• Multiple vulnerabilities in cPanel EasyApache
• SUSE Linux Enterprise Server update for apache2
• Debian update for apache2
• Red Hat JBoss Core Services update for httpd
• Red Hat Software Collections update for httpd24-httpd
• Red Hat Enterprise Linux 8 update for the httpd:2.4 module
• Red Hat Enterprise Linux 8.2 update for the httpd:2.4 module
• Red Hat Enterprise Linux 8.1 update for the httpd:2.4 module
• Amazon Linux AMI update for httpd24
• Red Hat Enterprise Linux 7 update for httpd
• Tenable.sc update for Apache HTTP Server
• SSRF in F5OS Apache component
• CentOS 7 update for httpd
• Multiple vulnerabilities in Cisco Security Manager
• Server-Side Request Forgery in Cisco TelePresence Video Communication Server and Expressway Series
• Server-Side Request Forgery (SSRF) in Oracle HTTP Server
• Multiple vulnerabilities in Oracle Enterprise Manager Ops Center
• Server-Side Request Forgery (SSRF) in Oracle Secure Global Desktop
• Multiple vulnerabilities in IBM Security SiteProtector System
• Multiple vulnerabilities in IBM DS8000 Hardware Management Console
• Multiple vulnerabilities in Siemens Products
• SUSE update for apache2
• SUSE update for apache2
• Ubuntu update for apache2
• Ubuntu update for apache2
• Ubuntu update for apache2
• Ubuntu update for apache2
• Multiple vulnerabilities in DELL Secure Connect Gateway Security
• Multiple vulnerabilities in Zimbra Collaboration
• Gentoo update for Apache HTTPD
• Multiple vulnerabilities in IBM HTTP Server
• Red Hat Software Collections update for httpd24-httpd
• SSRF in IBM Aspera Faspex
• Server-side request forgery in IBM Aspera Orchestrator
• Multiple vulnerabilities in Dell Unity, Dell UnityVSA, and Dell Unity XT
• openEuler update for httpd
• Red Hat Enterprise Linux 8 update for the httpd:2.4 module
• Fedora 34 update for httpd
• Fedora 35 update for httpd
• Multiple vulnerabilities in Dell XtremIO X2
• Multiple vulnerabilities in IBM Watson Studio on Cloud Pak for Data
• Multiple vulnerabilities in IBM Maximo Application Suite - IoT Component
• Anolis OS update for httpd:2.4 module