---
cve: "CVE-2021-40438"
severity: "CRITICAL"
cvss: 9.0
epss: "100%"
vendor: "Apache Software Foundation"
kev: true
exploited: true
published: "2021-09-16 15:15:07"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-09-04T00:30:48+02:00"
---

# CVE-2021-40438

> 9.0 CRITICAL · ⚠️ CISA KEV (1737 Tage) · 🔓 Exploited

## Beschreibung

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.

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Hoch | good |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Verändert | bad |
| C Vertraulichkeit | Hoch | bad |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Hoch | bad |

## Referenzen

- <https://httpd.apache.org/security/vulnerabilities_24.html>
- <https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SPBR6WUYBJNACHKE65SPL7TJOHX7RHWD/>
- <https://lists.apache.org/thread.html/r82838efc5fa6fc4c73986399c9b71573589f78b31846aff5bd9b1697%40%3Cusers.httpd.apache.org%3E>
- <https://lists.apache.org/thread.html/r82c077663f9759c7df5a6656f925b3ee4f55fcd33c889ba7cd687029%40%3Cusers.httpd.apache.org%3E>
- <https://lists.apache.org/thread.html/r3925e167d5eb1c75def3750c155d753064e1d34a143028bb32910432%40%3Cusers.httpd.apache.org%3E>
- <https://lists.apache.org/thread.html/r61fdbfc26ab170f4e6492ef3bd5197c20b862ce156e9d5a54d4b899c%40%3Cusers.httpd.apache.org%3E>
- <https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZNCYSR3BXT36FFF4XTCPL3HDQK4VP45R/>
- <https://lists.debian.org/debian-lts-announce/2021/10/msg00001.html>
- <https://lists.apache.org/thread.html/r2eb200ac1340f69aa22af61ab34780c531d110437910cb9c0ece3b37%40%3Cbugs.httpd.apache.org%3E>
- <https://www.debian.org/security/2021/dsa-4982>
- <https://lists.apache.org/thread.html/r210807d0bb55f4aa6fbe1512be6bcc4dacd64e84940429fba329967a%40%3Cusers.httpd.apache.org%3E>
- <https://lists.apache.org/thread.html/rf6954e60b1c8e480678ce3d02f61b8a788997785652e9557a3265c00%40%3Cusers.httpd.apache.org%3E>
- <https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-httpd-2.4.49-VWL69sWQ>
- <https://www.oracle.com/security-alerts/cpujan2022.html>
- <https://www.tenable.com/security/tns-2021-17>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2021-40438) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_