CVE-2021-42013

Known exploitThis CVE is high risk and there are known public exploits leveraging this vulnerability. Address this vulnerability with high priority.

Public on

Last Modified: UTC

Description

A path traversal and remote code execution flaw was found in Apache HTTP Server 2.4.49 and 2.4.50. A remote attacker could use this flaw to map URLs to files outside the expected document root. Additionally, this flaw could leak the source of interpreted files like CGI scripts. 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 paths, this could allow for remote code execution. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability. This is an incomplete fix for CVE-2021-41773.

A path traversal and remote code execution flaw was found in Apache HTTP Server 2.4.49 and 2.4.50. A remote attacker could use this flaw to map URLs to files outside the expected document root. Additionally, this flaw could leak the source of interpreted files like CGI scripts. 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 paths, this could allow for remote code execution. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability. This is an incomplete fix for CVE-2021-41773.

Statement

This issue only affects httpd 2.4.49 and 2.4.50, earlier versions are not affected. Therefore this issue does not affect the versions of httpd shipped with Red Hat products.

This issue only affects httpd 2.4.49 and 2.4.50, earlier versions are not affected. Therefore this issue does not affect the versions of httpd shipped with Red Hat products.

Additional information

  • Bugzilla 2011900: httpd: path traversal and remote code execution (incomplete fix of CVE-2021-41773)
  • CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
  • FAQ: Frequently asked questions about CVE-2021-42013

Common Vulnerability Scoring System (CVSS) Score Details

Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

The following CVSS metrics and score provided are preliminary and subject to review.

CVSS v3 Score Breakdown
Red HatNVD

CVSS v3 Base Score

8.1

9.8

Attack Vector

Network

Network

Attack Complexity

High

Low

Privileges Required

None

None

User Interaction

None

None

Scope

Unchanged

Unchanged

Confidentiality Impact

High

High

Integrity Impact

High

High

Availability Impact

High

High

CVSS v3 Vector

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

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

Frequently Asked Questions

Why is Red Hat's CVSS v3 score or Impact different from other vendors?

My product is listed as "Under investigation" or "Affected", when will Red Hat release a fix for this vulnerability?

What can I do if my product is listed as "Will not fix"?

What can I do if my product is listed as "Fix deferred"?

What is a mitigation?

I have a Red Hat product but it is not in the above list, is it affected?

Why is my security scanner reporting my product as vulnerable to this vulnerability even though my product version is fixed or not affected?

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