CASCACascade Atlas

Evidence dossier

CVE-2021-42013

Path Traversal and Remote Code Execution in Apache HTTP Server 2.4.49 and 2.4.50 (incomplete fix of CVE-2021-41773)

Exploited in the wild (CISA KEV since Nov 3, 2021). NVD reports CVSS 3.1 9.8. EPSS estimates 100.0% exploit likelihood as of Jul 26, 2026.

91.4–91.9Priority evidence range
Evidence current through Aug 27, 2026, 6:09 PM UTC

As of Aug 27, 2026

Normalized restatement

It was found that the fix for CVE-2021-41773 in Apache HTTP Server 2.4.50 was insufficient. 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 only affects Apache 2.4.49 and Apache 2.4.50 and not earlier versions.

State
PUBLISHED
Published
Oct 7, 2021
Updated
Oct 21, 2025
Evidence coverage
98%

Evidence chronology

What was known when

Download this view's receipt →
  1. Source dateSource date omittedFirst observed by CASCA
    apache

    Record text: Path Traversal and Remote Code Execution in Apache HTTP Server 2.4.49 and 2.4.50 (incomplete fix of CVE-2021-41773)

    Inspect raw assertion
    Field
    container
    Value
    Path Traversal and Remote Code Execution in Apache HTTP Server 2.4.49 and 2.4.50 (incomplete fix of CVE-2021-41773)
    Original evidence ↗
  2. Source dateSource date omittedFirst observed by CASCA
    CISA-ADP

    Record text: CISA ADP Vulnrichment

    Inspect raw assertion
    Field
    container
    Value
    CISA ADP Vulnrichment
    Original evidence ↗
  3. Source dateSource date omittedFirst observed by CASCA
    CVE Program

    Record text: CVE Program Container

    Inspect raw assertion
    Field
    container
    Value
    CVE Program Container
    Original evidence ↗
  4. Source dateFirst observed by CASCA
    CISA KEV

    Exploitation cataloged: Apache HTTP Server Path Traversal Vulnerability

    Inspect raw assertion
    Field
    observed_exploitation
    Value
    Apache HTTP Server Path Traversal Vulnerability
    Original evidence ↗
  5. Source dateFirst observed by CASCA
    FIRST EPSS

    EPSS score: 99.96% probability · 99.98th percentile

    Inspect raw assertion
    Field
    model_probability
    Value
    Probability 0.999640000000; percentile 0.999770000000
    Original evidence ↗
ExploitationCatalog member

CISA KEV · catalog date Nov 3, 2021 · first observed Jul 19, 2026

Exploit likelihood99.96%

FIRST EPSS · score date Jul 26, 2026 · 100th percentile · first observed Jul 27, 2026

SeverityCVSS 9.8

NVD · CVSS 3.1 · first observed Jul 19, 2026 · same-version scores align in this snapshot

Evidence detail

Source limits and decisions

Why each evidence state has this value

casca-unknown-reasons-v1
Exploitation statusEvidence supported

Eligible evidence is present for this bounded claim.

Revision
evidence-policy-v1.1.0
Cutoff
Aug 27, 2026
Resolution
None
Exploit likelihoodEvidence supported

Eligible evidence is present for this bounded claim.

Revision
evidence-policy-v1.1.0
Cutoff
Aug 27, 2026
Resolution
None
Severity assessmentEvidence supported

Eligible evidence is present for this bounded claim.

Revision
casca-direct-cvss-eligibility-v1
Cutoff
Aug 27, 2026
Resolution
None
Affected productsSource-reported scope

The cited source assertion is retained while canonical product linkage remains open.

Revision
casca-factor-d-obligations-v1
Cutoff
Aug 27, 2026
Resolution
Resolve identity

Source comparison

Who said what

apacheOriginal assertion
Record text

Path Traversal and Remote Code Execution in Apache HTTP Server 2.4.49 and 2.4.50 (incomplete fix of CVE-2021-41773)

Inspect raw assertion
Field
container
Value
Path Traversal and Remote Code Execution in Apache HTTP Server 2.4.49 and 2.4.50 (incomplete fix of CVE-2021-41773)
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
CISA-ADPIndependent enrichment
Record text

CISA ADP Vulnrichment

Inspect raw assertion
Field
container
Value
CISA ADP Vulnrichment
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
CVE ProgramDerivative copy
Record text

CVE Program Container

Inspect raw assertion
Field
container
Value
CVE Program Container
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
CISA KEVOriginal assertion
Exploitation cataloged

Apache HTTP Server Path Traversal Vulnerability

Inspect raw assertion
Field
observed_exploitation
Value
Apache HTTP Server Path Traversal Vulnerability
Source dateFirst observed by CASCAOriginal evidence ↗
FIRST EPSSOriginal assertion
EPSS score

99.96% probability · 99.98th percentile

Inspect raw assertion
Field
model_probability
Value
Probability 0.999640000000; percentile 0.999770000000
Source dateFirst observed by CASCAOriginal evidence ↗

Applicability

Cited product scope

Trace impact →
10Underlying assertions
6Canonical products
10Target assertions
0Constraint assertions

Grouped from 4 configuration nodes in this exact snapshot. Visual grouping is navigational; asset exposure and root cause require cited evidence.

Identity source boundaries
  • Cpe dictionary1,775,266 records · observed through 2026-07-21T06:45:29.809Z27d65b0f-b718-4b4f-bb79-c47c68d09dfa
  • Cpe match643,502 records · observed through 2026-07-21T08:13:17.697Z955dae73-7302-438b-aee1-058d7cc5d48e

7 scope groups

apache · source assertedApache Software FoundationApache HTTP ServerDirect source scope
Affected: Apache HTTP Server 2.4.49Affected: Apache HTTP Server 2.4.50
Source-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Inspect raw assertion[{"status": "affected", "version": "Apache HTTP Server 2.4.49"}, {"status": "affected", "version": "Apache HTTP Server 2.4.50"}]
NVD CPE · APPLICATIONapachehttp_serverVulnerable target · 2 assertions
Version 2.4.49; Version 2.4.50Canonical identity product-9ac1ed1c70311d36a45c72f8dd14128e1f8de18b347393d0fa18e946c202b58bLinked exact
Scope supported
Inspect raw assertions
  1. cpe:2.3:a:apache:http_server:2.4.50:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 1
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    f7e0afd3-d661-4631-86ab-d26f12083d1c
  2. cpe:2.3:a:apache:http_server:2.4.49:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    b201cfb2-f626-4dd0-9f6a-dfe8f64203e2
NVD CPE · OPERATING SYSTEMfedoraprojectfedoraVulnerable target · 2 assertions
Version 34; Version 35Canonical identity product-c96c7662a6606ed7594747da3d7ba9ee3a9758ab11658f6a3f42616361472e47Linked exact
Scope supported
Inspect raw assertions
  1. cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    1 · node/0 · match 1
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    80e516c0-98a4-4ade-b69f-66a772e2baaa
  2. cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    1 · node/0 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    a930e247-0b43-43cb-98ff-6ce7b8189835
NVD CPE · APPLICATIONnetappcloud_backupVulnerable target · 1 assertions
Version not applicableCanonical identity product-82c0ed89ab714a80f8d7ca4b0a7a5e6e1968a59a16c17a9f6a2a0a6a4757f6bfLinked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:a:netapp:cloud_backup:-:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    3 · node/0 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    5c2089ee-5d7f-47ec-8ea5-0f69790564c4
NVD CPE · APPLICATIONoracleinstantis_enterprisetrackVulnerable target · 3 assertions
Version 17.1; Version 17.2; Version 17.3Canonical identity product-5d00280b7e61e03519c1b83650a5d87f654dd625a18111d908ab01d840aacb09Linked exact
Scope supported
Inspect raw assertions
  1. cpe:2.3:a:oracle:instantis_enterprisetrack:17.3:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    2 · node/0 · match 2
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    7f69b9a5-f21b-4904-9f27-95c0f7a628e3
  2. cpe:2.3:a:oracle:instantis_enterprisetrack:17.1:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    2 · node/0 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    82ea4ba7-c38b-4af3-8914-9e3d089ebdd4
  3. cpe:2.3:a:oracle:instantis_enterprisetrack:17.2:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    2 · node/0 · match 1
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    b9c9bc66-fa5f-4774-9bda-7ab88e2839c4
NVD CPE · APPLICATIONoraclejd_edwards_enterpriseone_toolsVulnerable target · 1 assertions
Any version (unconstrained) (< 9.2.6.0)Canonical identity product-7c699e19a13f0273c993445d995a4520431edff8db1d821b2a216ecbcde3e979Linked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:a:oracle:jd_edwards_enterpriseone_tools:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    2 · node/0 · match 3
    Logic
    OR
    Version bounds
    through excluding 9.2.6.0
    Match ID
    86305e47-33e9-411c-b932-08c395c09982
NVD CPE · APPLICATIONoraclesecure_backupVulnerable target · 1 assertions
Any version (unconstrained) (< 18.1.0.1.0)Canonical identity product-737b9b881a28ecd3424e230b7274239f1f64a3d989f803d7e6ec102d32b3adb0Linked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:a:oracle:secure_backup:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    2 · node/0 · match 4
    Logic
    OR
    Version bounds
    through excluding 18.1.0.1.0
    Match ID
    c01e8b82-71c7-4a4a-a70a-7b147524ab4a

Affected-product evidence

Accepted scope and product mapping

6 canonical links · 1 source-reported links

Mapping establishedEvidence supported

vendor-b1377626da187dbea1eeb98f365c57a3dcbeccfdc2a7d3471e94ece7b6f88e55 · product-5d00280b7e61e03519c1b83650a5d87f654dd625a18111d908ab01d840aacb09

Source class
Nvd cpe vulnerable target
Assertions
3
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
17d1b0b3-2412-4529-8bca-ca657a0aa832e12d5d09-5459-49f8-a895-060dfae5c175e8bb490e-f765-4abe-b1b8-f4bfdf4206a7
Mapping establishedEvidence supported

vendor-b1377626da187dbea1eeb98f365c57a3dcbeccfdc2a7d3471e94ece7b6f88e55 · product-737b9b881a28ecd3424e230b7274239f1f64a3d989f803d7e6ec102d32b3adb0

Source class
Nvd cpe vulnerable target
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
f8802923-81b0-46f1-94f5-8125d29cbf04
Mapping establishedEvidence supported

vendor-b1377626da187dbea1eeb98f365c57a3dcbeccfdc2a7d3471e94ece7b6f88e55 · product-7c699e19a13f0273c993445d995a4520431edff8db1d821b2a216ecbcde3e979

Source class
Nvd cpe vulnerable target
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
53a89d33-7d6d-4345-9e0e-a6cd8010d669
Mapping establishedEvidence supported

vendor-d1dcf2e2192106a1eb34744930a80b83005fa5d60195c923256e69ac39974aed · product-82c0ed89ab714a80f8d7ca4b0a7a5e6e1968a59a16c17a9f6a2a0a6a4757f6bf

Source class
Nvd cpe vulnerable target
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
149e5b30-c642-46ba-9167-e0c4beece581
Mapping establishedEvidence supported

vendor-8771dac0ae5eeec984ca23e4bbe5a243fb7896ad7c1c4afc6acd3abe53fdd152 · product-9ac1ed1c70311d36a45c72f8dd14128e1f8de18b347393d0fa18e946c202b58b

Source class
Nvd cpe vulnerable target
Assertions
2
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
5cca4139-7b21-4be2-8700-aa40ca762bf48098e619-0c3d-43d3-beed-2783d826facf
Mapping establishedEvidence supported

vendor-2d566b06907460b10e6e48c8544126e19f1d6df137983056edae8d0b51e34e45 · product-c96c7662a6606ed7594747da3d7ba9ee3a9758ab11658f6a3f42616361472e47

Source class
Nvd cpe vulnerable target
Assertions
2
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
5e6b4e6b-4193-4b58-9575-5029c9aa11b0c0eb0d2c-a33c-466b-a52f-206588a22315
Source-reported scopeSource-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Vendor specified only by source · Product specified only by source

Source class
Direct cve affected
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
907e4269-7fe0-4d19-bc51-c02f2bad7d6d

Assessments

CVSS by origin

9.8
NVDCVSS 3.1 · role Primary · priority eligiblevalid_matchCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5
NVDCVSS 2.0 · role Primary · priority eligiblevalid_matchAV:N/AC:L/Au:N/C:P/I:P/A:P
9.8
CVE Program sourceCVSS 3.1 · role Secondary · priority eligiblevalid_matchCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8
CISA-ADPCVSS 3.1 · role unknown · display onlyDirect record assessment retained outside normalized eligibilityCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Direct CVE/CNA normalized decisions

9.8Priority eligible

CISA-ADP

CVSS 3.1 · Secondary · Independent enrichment · rank 2

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Validation
Valid match
Recomputed
9.8
Decision reason
Evidence supported
Policy
casca-direct-cvss-eligibility-v1

Assessments are retained side by side under closed precedence. Cascade never averages CVSS.

Evidence boundaries

  • 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; remaining scope stays source-scoped.
  • NVD-carried upstream facts remain derivative; independent corroboration requires a separately authored source.
  • 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.
  • Core replay supports the active and immediately prior generation; retrospective valid-at replay is deferred.
  • OSV aggregation and OSV-converted NVD material are not independent corroboration.
  • Red Hat facts are vendor assertions for the exact supplied products.
  • Nonmembership and not-yet-observed states are not proof of safety.