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Fencer Vulns
critical 9.8

CVE-2020-13927 kev in the critical feed json

Authentication bypass in Apache Airflow

published 2020-11-10 5 y ago modified 2026-09-08 2 mo ago also BIT-airflow-2020-13927 , EUVD-2020-0037 , GHSA-hhx9-p69v-cx2j , PYSEC-2020-18

cvss
9.8
version 3.1, CNA
cisa kev
Exploited
added 2022-01-18
epss
99.8%
EPSS 99.8% chance of exploitation in 30 days, percentile 99.9%
public exploits
2
Metasploit, Exploit-DB, plus a Nuclei check

Summary

The previous default setting for Airflow's Experimental API was to allow all API requests without authentication, but this poses security risks to users who miss this fact. From Airflow 1.10.11 the default has been changed to deny all requests by default and is documented at https://airflow.apache.org/docs/1.10.11/security.html#api-authentication. Note this change fixes it for new installs but existing users need to change their config to default `[api]auth_backend = airflow.api.auth.backend.deny_all` as mentioned in the Updating Guide: https://github.com/apache/airflow/blob/1.10.11/UPDATING.md#experimental-api-will-deny-all-request-by-default

Patch / fix

cisa required action Apply updates per vendor instructions.

  • pypi apache-airflow 1.10.11
  • bitnami airflow 1.10.11
  • apache airflow 1.10.11

Timeline

  1. First public exploit (Metasploit exploit/linux/http/apache_airflow_dag_rce)
  2. Published
  3. Added to CISA KEV
  4. CISA patch deadline
  5. CISA SSVC: exploitation active

Known exploited

Added
4 y ago
Patch by
2022-07-18 (4 y ago)
Ransomware
Not known
Required action
Apply updates per vendor instructions.
Vendor, product
Apache, Airflow's Experimental API
CISA name
Apache Airflow's Experimental API Authentication Bypass

CISA SSVC

Exploitation
Active, exploited in the wild
Automatable
yes
Technical impact
total
Assessed
2 y ago

Exploit prediction

99.78% chance of exploitation in the next 30 days, higher than 99.9% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • Metasploit exploit/linux/http/apache_airflow_dag_rce Apache Airflow 1.10.10 - Example DAG Remote Code Execution metasploit exploit, excellent rank, 2020-07-14
  • EDB-49927 Apache Airflow 1.10.10 - 'Example Dag' Remote Code Execution webapps, 2021-06-02
  • Nuclei template Airflow Experimental <1.10.11 - REST API Auth Bypass nuclei detection template
  • packetstormsecurity.com http://packetstormsecurity.com/files/162908/Apache-Airflow-1.10.10-Remote-Code-Execution.html referenced PoC, tagged "exploit" by a source, unverified
  • packetstormsecurity.com http://packetstormsecurity.com/files/174764/Apache-Airflow-1.10.10-Remote-Code-Execution.html referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CISA ADP 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
GitHub 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E: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
CNA 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
<1.10.11
1.10.11
bitnami airflow
<1.10.11
1.10.11

Affected products

  • n/a Apache Airflow
  • apache airflow

Classification

Weakness
  • CWE-306 Missing Authentication for Critical Functionality
  • CWE-1188 Initialization of a Resource with an Insecure Default
  • CWE-1056 Invokable Control Element with Variadic Parameters
  • CWE-287 Improper Authentication

References

Sources

Fencer Vulns 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.