CVE Tools
Sign in

CVE-2021-41773

Path traversal and file disclosure vulnerability in Apache HTTP Server 2.4.49

Published: Oct 5, 2021Updated: Feb 17, 2026 Sources: CVE List NVD BDUCWE-22
NVD MITRE
9.8CVSSCRITICAL
EPSS Score
100.0%
Top 0.0%
CISA KEV
Active Exploitation
Since Nov 3, 2021
Exploits
6 Known
Remediation
Patch Available
Am I actually vulnerable?1 Nuclei template available — see how to check your systems. How to verify

Description

A flaw was found in a change made to path normalization in Apache HTTP Server 2.4.49. An attacker could use a path traversal attack to map URLs to files outside the directories configured by Alias-like directives. If files outside of these directories are not protected by the usual default configuration "require all denied", these requests can succeed. If CGI scripts are also enabled for these aliased pathes, this could allow for remote code execution. This issue is known to be exploited in the wild. This issue only affects Apache 2.4.49 and not earlier versions. The fix in Apache HTTP Server 2.4.50 was found to be incomplete, see CVE-2021-42013.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:HI:HA:H
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:HConfidentiality
High
I:HIntegrity
High
A:HAvailability
High
Open in CVSS calculator →

Weaknesses

CWE-22

Affected Products

Instantis EnterpriseTrackOracle Corp.
On-premWeb App
Enterprise Software / itsm-monitoring
Debian GNU/LinuxСообщество свободного программного обеспечения
On-premOS
Operating Systems / linux-distro
Cloud BackupNetApp Inc.Hardware Firmware
openSUSE TumbleweedNovell Inc.
On-premOS
Operating Systems / linux-distro
FedoraFedora Project
On-premOS
Operating Systems / linux-distro
oracle corp.commercialUSDatabasesaka oracle
сообщество свободного программного обеспеченияoss-projectOperating Systemsaka сообщество свободного программного обеспечения, fsf
netapp inc.commercialUSHardware Firmwareaka netapp
novell inc.commercialUSOperating Systems
fedora projectoss-projectUSOperating Systemsaka fedora
and 9 more affected products View all →

Attack Graph

Products CVE Techniques Tactics

Click technique nodes to view MITRE ATT&CK details. Scroll to zoom, drag to pan.

Exploitability

CISA Known Exploited Vulnerability
Added to KEV:Nov 3, 2021
Remediation due:Nov 17, 2021
Ransomware:Known ransomware use

Required action: Apply updates per vendor instructions.

6 exploit sources identified

Exploit details including PoC links, Metasploit modules, and scanner templates are available after registration.

View exploit details
Official Patch Available

MITRE ATT&CK

2 techniques
Collection
Discovery
View detailed technique mapping

References

https://httpd.apache.org/security/vulnerabilities_24.html
httpd.apache.org
https://github.com/pld-linux/apache/commit/9ff0bac043c0d5cb3517e7f7ef15a723549dd087
github.com
https://xakep.ru/2021/10/05/apache-path-traversal/
xakep.ru
and 43 more references View all →

Timeline

Published
Oct 5, 2021
Added to CISA KEV
Nov 3, 2021
Last Updated
Feb 17, 2026

Unlock Complete Vulnerability Intelligence

Get the full picture for CVE-2021-41773 and every CVE in our database. Create a free account — no credit card required.

Create Free Account
Plain-language analysis
Impact assessment and exploitation scenario in plain English
Attack graph visualization
Interactive attack path and kill chain mapping
Exploit details & PoC links
ExploitDB, Metasploit, GitHub PoCs with direct links
Nuclei scanner templates
Ready-to-use vulnerability scanner templates
Full remediation guide
Patch instructions, workarounds, and compliance impact
Interactive AI chat
Ask questions about this vulnerability in natural language
Related vulnerabilities
Semantically similar CVEs and attack patterns
REST API & MCP access
Integrate vulnerability data into your workflows