Apache HTTP Server vulnerable to directory traversal


Apache HTTP Server provided by The Apache Software Foundation contains a directory traversal vulnerability (CWE-22).

Shungo Kumasaka of Internet Initiative Japan Inc. reported this vulnerability to the developer, and also to IPA in order to notify users of its solution through JVN.
JPCERT/CC coordinated with the developer under Information Security Early Warning Partnership.
CVSS Severity (What is CVSS?)

CVSS V3 Severity:
Base Metrics 7.5 (High) [IPA Score]
  • Attack Vector: Network
  • Attack Complexity: Low
  • Privileges Required: None
  • User Interaction: None
  • Scope: Unchanged
  • Confidentiality Impact: High
  • Integrity Impact: None
  • Availability Impact: None
CVSS V2 Severity:
Base Metrics 5.0 (Medium) [IPA Score]
  • Access Vector: Network
  • Access Complexity: Low
  • Authentication: None
  • Confidentiality Impact: Partial
  • Integrity Impact: None
  • Availability Impact: None
Affected Products

Apache Software Foundation
  • Apache HTTP Server 2.4.49 and 2.4.50


A remote attacker may access the unprotected files in "require all denied" placed outside of the document root.
Moreover, if CGI scripts are enabled, arbitrary code may be executed.

[Update the Software]
Update to the latest version according to the information provided by the developer.
Vendor Information

Apache Software Foundation
CWE (What is CWE?)

  1. Path Traversal(CWE-22) [IPA Evaluation]
CVE (What is CVE?)

  1. CVE-2021-42013

  1. JVN : JVN#51106450
  2. IPA SECURITY ALERTS : Security Alert for Vulnerability in Apache HTTP Server (JVN#51106450) (in Japanese)
  3. JPCERT : [Updated] Alert Regarding Path Traversal Vulnerability (CVE-2021-41773) in Apache HTTP Server
Revision History

  • [2021/10/11]
      Web page was published