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Fencer Intel
critical 9.8

CVE-2021-38540 in the critical feed json

Apache Airflow: Variable Import endpoint missed authentication check

published 5y ago modified 2mo ago also BIT-airflow-2021-38540 , EUVD-2021-0016 , GHSA-h88f-r7cw-8fv3 , PYSEC-2021-326

cvss
9.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
80.9%
EPSS 80.9% chance of exploitation in 30 days, percentile 99.6%
public exploits
0
none known, plus a Nuclei check

Summary

The variable import endpoint was not protected by authentication in Airflow >=2.0.0, <2.1.3. This allowed unauthenticated users to hit that endpoint to add/modify Airflow variables used in DAGs, potentially resulting in a denial of service, information disclosure or remote code execution. This issue affects Apache Airflow >=2.0.0, <2.1.3.

Patch / fix

  • pypi apache-airflow 2.1.3
  • bitnami airflow 2.1.3
  • Apache Software Foundation Apache Airflow 2.1.3

Is CVE-2021-38540 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Exploit prediction

80.94% chance of exploitation in the next 30 days, higher than 99.6% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • Nuclei template Apache Airflow - Unauthenticated Variable Import nuclei detection template

CVSS scores

assigned by version score vector
GitHub 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P
OSV 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
pypi apache-airflow
>=2.0.0, <2.1.3
2.1.3
bitnami airflow
>=2.0.0, <2.1.3
2.1.3

Affected products

  • Apache Software Foundation Apache Airflow

Classification

Weakness
  • CWE-269 Improper Privilege Management
  • CWE-306 Missing Authentication for Critical Functionality

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.