CVE-2021-41773
Apache HTTP Server Path Traversal Vulnerability
What is affected
| Vendor | Apache |
|---|---|
| Product | HTTP Server |
| Weakness | CWE-22 |
The vulnerability
Apache HTTP Server contains a path traversal vulnerability that allows an attacker to perform remote code execution if files outside directories configured by Alias-like directives are not under default �require all denied� or if CGI scripts are enabled. The original patch issued under this CVE ID is insufficient, please review remediation information under CVE-2021-42013.
Required action
Apply updates per vendor instructions.
US federal civilian agencies were required to act by 17 November 2021 under BOD 22-01. The deadline is a compliance date, not a measure of severity — it says nothing about how dangerous the flaw is to anyone else.
Ransomware
CISA records this vulnerability as having been used in ransomware campaigns. That is a confirmed observation, not an assessment of likelihood.
Where this comes from
Every field on this page is taken from the CISA Known Exploited Vulnerabilities catalog, last synced 12 Nov 2026, 00:29. Nothing here is our own assessment. For the technical scoring, see the NVD record below.
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