CASCACascade Atlas

Evidence dossier

CVE-2021-41773

Path traversal and file disclosure vulnerability in Apache HTTP Server 2.4.49

70.7–99.5Priority evidence range
As known Jul 19, 2026, 5:00 AM UTCgen-56ccdaf9

Normalized restatement

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.

State
PUBLISHED
Published
Oct 5, 2021
Updated
Oct 21, 2025
Evidence coverage
72%
CISA KEVCatalog member

Apply updates per vendor instructions.

FIRST EPSS99.99%

2026-07-18 · v2026.06.15 · percentile 100.0%

Source stateConflict visible

Distinct CVSS assessments remain side by side; none are averaged.

Source comparison

Who said what

apacheoriginal assertion
container

Path traversal and file disclosure vulnerability in Apache HTTP Server 2.4.49

CISA-ADPindependent enrichment
container

CISA ADP Vulnrichment

CVEderivative copy
container

CVE Program Container

CISA KEVoriginal assertion
observed_exploitation

Apache HTTP Server Path Traversal Vulnerability

FIRST EPSSoriginal assertion
model_probability

Probability 0.999920000000; percentile 0.999850000000

Applicability

Cited product scope

Trace impact →
Apache Software FoundationApache HTTP Server
[{"status": "affected", "version": "Apache HTTP Server 2.4 2.4.49"}]unknown
Unknown vendorUnknown product
cpe:2.3:a:apache:http_server:2.4.49:*:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:a:netapp:cloud_backup:-:*:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:a:oracle:instantis_enterprisetrack:17.1:*:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:a:oracle:instantis_enterprisetrack:17.2:*:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:a:oracle:instantis_enterprisetrack:17.3:*:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*supported

Assessments

CVSS by origin

9.8
nvd@nist.govCVSS 3.1 · role PrimaryCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
4.3
nvd@nist.govCVSS 2.0 · role PrimaryAV:N/AC:M/Au:N/C:P/I:N/A:N
7.5
134c704f-9b21-4f2e-91b3-4a467353bcc0CVSS 3.1 · role SecondaryCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
7.5
CISA-ADPCVSS 3.1 · role unknownCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Limitations and unknowns

  • KEV membership is authoritative for the catalog, not proof of exposure in any environment.
  • EPSS is a dated model probability and not an individual-environment prediction.
  • Affected or fixed status applies only to the exact cited product and version scope; unresolved scope remains unknown.
  • NVD-carried upstream facts remain derivative and are not independent corroboration.
  • Only NVD metrics validated under the generation-bound calculator are Public Priority eligible; direct CVE record metrics remain display-only.
  • NVD CVSS source eligibility is closed: NVD-authored, exact record-source, or registered same-CVE container origin; unmapped sources remain display-only.
  • Factor D is unknown in Public Core because no accepted canonical mapping-obligation ledger is present.
  • Core replay supports the active and immediately prior generation; retrospective valid-at replay is deferred.