CRITICALCVSS 9.0Actively exploited · CISA KEV since 2021-12-01Vulnerability

CVE-2021-40438

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.

Properties

Euvd product
Apache HTTP Server
Vulnerability name
Apache HTTP Server-Side Request Forgery (SSRF)
First seen
2026-08-06T03:55:20+00:00
Cvss score
9
Epss score
0.99999
Last seen
2026-10-19T12:00:27+00:00
Due date
2021-12-15
Euvd assigner
apache
Retrieved at
2026-10-21T01:24:47+00:00
Exploited euvd since
2021-12-01T00:00:00+00:00
Src batch id
epss_history-20261020T103617Z-728ddd
Source url
https://epss.empiricalsecurity.com/epss_scores-2026-10-19.csv.gz
Date added
2021-12-01
Euvd base score version
3.1
Score
9
Fetched at
2026-10-20T10:36:20+00:00
Euvd vendor
Apache Software Foundation
Cvss vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
In Signal since
initial import (Sep 2026)
Euvd base score
9

Related Entities (87 · showing 23)

AFFECTS_PRODUCT (84 · showing 20)

→[Product]cpe:2.3:o:redhat:enterprise_linux_server_tus:8.8:*:*:*:*:*:*:*
→[Product]cpe:2.3:a:oracle:instantis_enterprisetrack:17.2:*:*:*:*:*:*:*
→[Product]cpe:2.3:o:broadcom:brocade_fabric_operating_system_firmware:-:*:*:*:*:*:*:*
→[Product]cpe:2.3:a:oracle:zfs_storage_appliance_kit:8.8:*:*:*:*:*:*:*
→[Product]cpe:2.3:a:oracle:enterprise_manager_ops_center:12.4.0.0:*:*:*:*:*:*:*
→[Product]cpe:2.3:a:siemens:sinema_remote_connect_server:3.2:*:*:*:*:*:*:*
→[Product]cpe:2.3:a:siemens:sinema_server:14.0:-:*:*:*:*:*:*
→[Product]cpe:2.3:a:oracle:secure_global_desktop:5.6:*:*:*:*:*:*:*
→[Product]cpe:2.3:a:oracle:http_server:12.2.1.3.0:*:*:*:*:*:*:*
→[Product]cpe:2.3:a:oracle:instantis_enterprisetrack:17.1:*:*:*:*:*:*:*
→[Product]cpe:2.3:a:netapp:cloud_backup:-:*:*:*:*:*:*:*
→[Product]cpe:2.3:a:tenable:tenable.sc:*:*:*:*:*:*:*:*
→[Product]cpe:2.3:a:siemens:ruggedcom_nms:*:*:*:*:*:*:*:*
→[Product]cpe:2.3:a:netapp:storagegrid:-:*:*:*:*:*:*:*
→[Product]cpe:2.3:a:siemens:sinec_nms:*:*:*:*:*:*:*:*
→[Product]cpe:2.3:a:netapp:clustered_data_ontap:-:*:*:*:*:*:*:*
→[Product]cpe:2.3:a:oracle:http_server:12.2.1.4.0:*:*:*:*:*:*:*
→[Product]cpe:2.3:a:oracle:instantis_enterprisetrack:17.3:*:*:*:*:*:*:*
→[Product]cpe:2.3:a:siemens:sinema_remote_connect_server:*:*:*:*:*:*:*:*
→[Product]cpe:2.3:o:f5:f5os:*:*:*:*:*:*:*:*

DESCRIBES (1)

←[KEVEntry]Apache HTTP Server-Side Request Forgery (SSRF)

HAS_WEAKNESS (1)

→[Weakness]Server-Side Request Forgery (SSRF)

INVOLVES (1)

←[Signal]kev_added · 2021-12-01

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CVE-2021-40438 (CVSS 9) — Ninja Signal Threat Intelligence | Ninja Signal