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CVE-2023-39441· NVD / CVE Program· CNA apache

Apache Airflow SMTP Provider, Apache Airflow IMAP Provider, Apache Airflow: SMTP/IMAP client components allowed MITM due to missing Certificate Validation

Apache Airflow SMTP Provider before 1.3.0, Apache Airflow IMAP Provider before 3.3.0, and Apache Airflow before 2.7.0 are affected by the Validation of OpenSSL Certificate vulnerability. The default SSL context with SSL library did not check a server's X.509 certificate.  Instead, the code accepted any certificate, which could result in the disclosure of mail server credentials or mail contents when the client connects to an attacker in a MITM position. Users are strongly advised to upgrade to Apache Airflow version 2.7.0 or newer, Apache Airflow IMAP Provider version 3.3.0 or newer, and Apache Airflow SMTP Provider version 1.3.0 or newer to mitigate the risk associated with this vulnerability

MediumCVSS 5.9 · v3.1—No exploit Fix available
Published
Aug 23, 2023
Updated
Jun 17, 2026
EPSS
0.8% · 55th percentile
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Report tools

JSON

Action score

23

Monitor

Low priority for now.

CVSS
23 / 40 · 5.9 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.8%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Affected systems

VendorProduct
apacheairflow
apacheapache-airflow-providers-imap
apacheapache-airflow-providers-smtp

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • apache airflowbefore 2.7.0
  • apache apache-airflow-providers-imapbefore 3.3.0
  • apache apache-airflow-providers-smtpbefore 1.3.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (apache). Independent of NVD's CPE analysis and usually ahead of it.

  • Apache Software Foundation Apache Airflow

    • before 2.7.0affected · semver

  • Apache Software Foundation Apache Airflow IMAP Provider

    • before 3.3.0affected · semver

  • Apache Software Foundation Apache Airflow SMTP Provider

    • before 1.30affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
PyPIapache-airflowbefore 2.7.02.7.0
PyPIapache-airflow-providers-imapbefore 3.3.03.3.0
PyPIapache-airflow-providers-smtpbefore 1.3.01.3.0

Same product

apache: all records

Other highest-scoring records for the same primary product.

  • CVE-2020-13927The previous default setting for Airflow's Experimental API was to allow all API requests without authentication, but this poses security riKEV
    99Now
  • CVE-2020-11978An issue was found in Apache Airflow versions 1.10.10 and below.KEV
    95Now
  • CVE-2021-38540Apache Airflow: Variable Import endpoint missed authentication check
    63This week
  • CVE-2022-40127Apache Airflow <2.4.0 has an RCE in a bash example
    61This week
  • CVE-2022-24288Apache Airflow: RCE in example DAGs
    58Plan
  • CVE-2020-11981An issue was found in Apache Airflow versions 1.10.10 and below.
    50Plan

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Apache Software Foundation Apache Airflow2.7.0Vendor (CNA)
Apache Software Foundation Apache Airflow IMAP Provider3.3.0Vendor (CNA)
Apache Software Foundation Apache Airflow SMTP Provider1.30Vendor (CNA)
PyPI:apache-airflow2.7.0Package registry (OSV)
PyPI:apache-airflow-providers-imap3.3.0Package registry (OSV)
PyPI:apache-airflow-providers-smtp1.3.0Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • Special conditions such as timing or configuration are required.

If successful

Confidentiality
high · data can be read
Integrity
none
Availability
none
Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
None
Availability impact
None

Weakness class (CWE)

CWE-295 · Improper Certificate Validation

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

nvd-primary

Root cause

A certificate validation error is silently swallowed instead of terminating the connection. Often, code added for a test environment makes its way into production.

The bug in code

The whole CWE-295 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

kotlin
override fun checkServerTrusted(chain: Array<X509Certificate>, type: String) {  // Left empty for the test environment}

Fixed

kotlin
val client = OkHttpClient.Builder()  .certificatePinner(    CertificatePinner.Builder()      .add("api.sirius.example", "sha256/…")      .build()  ).build()

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Noroxi analysis

No Noroxi analysis for this record yet

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Change log

  1. Fix✗ → ✓

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References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records