critical Known exploitedREV. 01

CVE-2021-41773Apache 2.4.49 — Path Traversal to Code Execution

A change to path handling in one Apache release lets a crafted address escape the configured directories, reading files outside them and, where scripts are enabled, running them.

YOUR NEXT MOVE

Upgrade Apache past 2.4.49, and check whether script execution was enabled on any aliased directory.

Read the risk

THE VITAL STATS
CVSS score
9.8/ 10
CVSS v3.1
EPSS probability
100%
Likelihood of exploitation
Attack complexity
Low
Conditions needed to exploit
Known exploited
Yes — CISA KEV
CVE published
2021-10-05
Added to KEV
2021-11-03
Exploit published
Yes
Confidence
high
Kill chain
initial access
MITRE ATT&CK
T1190, T1083
Severity
critical

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

Attacker needsNetwork access to the server, with an aliased directory configured

Behind the card

5 REFERENCES
Field-level provenanceTRACE THE SOURCES +

Which source supports each field, when it was retrieved, and who extracted it.

FieldsSourceRetrievedExtractorConfidence
cvss, exploitation.attack_complexity, exploitation.exploit_available, references, published_atnvd.nist.gov2026-08-07scrty-crds-pipeline/0.1high
exploitation.known_exploited, exploitation.kev_addedcisa.gov2026-08-07scrty-crds-pipeline/0.1high
epssapi.first.org2026-08-07scrty-crds-pipeline/0.1high
title, summary, severity, remediation, mitre_attack, kill_chain, recommended_action, confidence, tags, exploitation.prerequisitesnvd.nist.gov2026-08-07claude-codehigh

Printing history

THE RECORD
  1. r1Initial base card

First printing. This card has not been reprinted since publication.

crds:cve-2021-41773 · CRDS 0.1 · Issued 2026-08-07