CVE-2021-35936Network attack vector

DAG log disclosure via unauthenticated log server

Published Aug 16, 2021 · Updated Aug 4, 2024

Information disclosure in Apache Airflow before 2.1.2 allows remote attackers to read DAG job logs through the worker log server. When remote logging is disabled, serve_logs starts a Flask application on the worker or scheduler, binds it to 0.0.0.0, and returns requested log files without authenticating the caller. Exposure requires CeleryExecutor or LocalExecutor with the log server reachable; access is read-only, but DAG logs can contain sensitive data.

CVSS severity5.3
Medium
EPSS probability5.45%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Apache Airflow before 2.1.2 allows remote attackers to read DAG job logs through the worker log server. When remote logging is disabled, serve_logs starts a Flask application on the worker or scheduler, binds it to 0.0.0.0, and returns requested log files without authenticating the caller. Exposure requires CeleryExecutor or LocalExecutor with the log server reachable; access is read-only, but DAG logs can contain sensitive data.

The record

CVE
CVE-2021-35936
Published
Aug 16, 2021
Updated
Aug 4, 2024
Vendor
The Apache Software Foundation
Product
Apache Airflow
Classifications
CWE-306, CWE-200, T1005
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 16, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Apache Airflow <2.1.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Apache Software Foundation · Apache Airflowversion=Apache Airflow <2.1.2

Published CVSS scores

5.3National Institute of Standards and TechnologyCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
5.0National Institute of Standards and TechnologyAV:N/AC:L/Au:N/C:P/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-306Missing Authentication for Critical Function
CWE-200Exposure of Sensitive Information to an Unauthorized Actor
T1005Data from Local System

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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