How serious is CVE-2021-41773?

This vulnerability has a CVSS score of 9.8 out of 10, classified as CRITICAL severity. Proof-of-concept exploit code is publicly available, making this an active threat.

Is there exploit code available for CVE-2021-41773?

Yes, proof-of-concept exploit code for CVE-2021-41773 is publicly available on GitHub and security research platforms. This increases the risk of active exploitation.

Which products are affected by CVE-2021-41773?

CVE-2021-41773 affects apache http server. Check the full CVE details for specific version information.

How do I fix CVE-2021-41773?

To remediate CVE-2021-41773, check for security patches from apache. Apply all available updates and security patches. If no patch is available, implement recommended workarounds or security controls to mitigate the risk.

CVE-2021-41773

Critical

|9.8

Exploit Available

Plain English Summary

AI-powered analysis for quick understanding

This vulnerability allows an attacker to access files outside of the intended directories on an Apache HTTP Server, potentially leading to remote code execution if certain scripts are enabled. This can happen if the server is misconfigured and does not properly restrict access to these files.

Technical 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 Analysis

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

Confidentiality ImpactHigh

Integrity ImpactHigh

Availability ImpactHigh

ScopeUnchanged

Vector String

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

Exploit Resources

Search for proof-of-concept code and exploit modules

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Official References

NIST NVD

Est. Bounty

$13,000($5K-$15K)

Vendor Response

Grade FPatched in 1596 days

Quick Information

Published

Oct 5, 2021

over 4 years ago

Last Modified

Feb 17, 2026

3 days ago

Vendor

apache

Product

http server