CVE-2021-40438

Published Sep 16, 2021

Last updated 6 months ago

Exploit knownCVSS critical 9.0
HTTP

Overview

Description
A crafted request uri-path can cause mod_proxy to forward the request to an origin server choosen by the remote user. This issue affects Apache HTTP Server 2.4.48 and earlier.
Source
security@apache.org
NVD status
Analyzed
Products
rocky_linux, jboss_core_services, software_collections, enterprise_linux, enterprise_linux_eus, enterprise_linux_for_arm_64, enterprise_linux_for_arm_64_eus, enterprise_linux_for_ibm_z_systems, enterprise_linux_for_ibm_z_systems_eus, enterprise_linux_for_ibm_z_systems_eus_s390x, enterprise_linux_for_power_big_endian, enterprise_linux_for_power_little_endian, enterprise_linux_for_power_little_endian_eus, enterprise_linux_for_scientific_computing, enterprise_linux_server, enterprise_linux_server_aus, enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions, enterprise_linux_server_tus, enterprise_linux_server_update_services_for_sap_solutions, enterprise_linux_update_services_for_sap_solutions, enterprise_linux_workstation, http_server, fedora, debian_linux, cloud_backup, clustered_data_ontap, storagegrid, brocade_fabric_operating_system_firmware, f5os, enterprise_manager_ops_center, http_server, instantis_enterprisetrack, secure_global_desktop, zfs_storage_appliance_kit, ruggedcom_nms, sinec_nms, sinema_remote_connect_server, sinema_server, tenable.sc

Risk scores

CVSS 3.1

Type
Primary
Base score
9
Impact score
6
Exploitability score
2.2
Vector string
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
Severity
CRITICAL

CVSS 2.0

Type
Primary
Base score
6.8
Impact score
6.4
Exploitability score
8.6
Vector string
AV:N/AC:M/Au:N/C:P/I:P/A:P

Known exploits

Data from CISA

Vulnerability name
Apache HTTP Server-Side Request Forgery (SSRF)
Exploit added on
Dec 1, 2021
Exploit action due
Dec 15, 2021
Required action
Apply updates per vendor instructions.

Weaknesses

security@apache.org
CWE-918
nvd@nist.gov
CWE-918

Social media

Hype score
Not currently trending

Configurations

Related CVEs

  1. Vulnerability in the Oracle HTTP Server product of Oracle Fusion Middleware (component: Core). Supported versions that are affected are 12.2.1.4.0 and 14.1.2.0.0. Difficult to exploit vulnerability allows unauthenticated attacker with network access via HTTP to compromise Oracle HTTP Server. While the vulnerability is in Oracle HTTP Server, attacks may significantly impact additional products (scope change). Successful attacks of this vulnerability can result in unauthorized creation, deletion or modification access to critical data or all Oracle HTTP Server accessible data as well as unauthorized access to critical data or complete access to all Oracle HTTP Server accessible data. CVSS 3.1 Base Score 8.7 (Confidentiality and Integrity impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N).•CVE-2026-34291
  2. In Eclipse Jetty, the HTTP/1.1 parser is vulnerable to request smuggling when chunk extensions are used, similar to the "funky chunks" techniques outlined here: * https://w4ke.info/2025/06/18/funky-chunks.html * https://w4ke.info/2025/10/29/funky-chunks-2.html Jetty terminates chunk extension parsing at \r\n inside quoted strings instead of treating this as an error. POST / HTTP/1.1 Host: localhost Transfer-Encoding: chunked 1;ext="val X 0 GET /smuggled HTTP/1.1 ... Note how the chunk extension does not close the double quotes, and it is able to inject a smuggled request.•CVE-2026-2332
  3. A flaw was found in tar. A remote attacker could exploit this vulnerability by crafting a malicious archive, leading to hidden file injection with fully attacker-controlled content. This bypasses pre-extraction inspection mechanisms, potentially allowing an attacker to introduce malicious files onto a system without detection.•CVE-2026-5704
  4. A flaw was found in libinput. A local attacker who can place a specially crafted Lua bytecode file in certain system or user configuration directories can bypass security restrictions. This allows the attacker to run unauthorized code with the same permissions as the program using libinput, such as a graphical compositor. This could lead to the attacker monitoring keyboard input and sending that information to an external location.•CVE-2026-35093
  5. A flaw was found in libinput. An attacker capable of deploying a Lua plugin file in specific system directories can exploit a dangling pointer vulnerability. This occurs when a garbage collection cleanup function is called, leaving a pointer that can then be printed to system logs. This could potentially expose sensitive data if the memory location is re-used, leading to information disclosure. For this exploit to work, Lua plugins must be enabled in libinput and loaded by the compositor.•CVE-2026-35094

References

Sources include official advisories and independent security research.