Apache Flink Improper Access Control Vulnerability
Apache Software Foundation — Apache Flink
A change introduced in Apache Flink 1.11.0 (and released in 1.11.1 and 1.11.2 as well) allows attackers to read any file on the local filesystem of the JobManager through the REST interface of the JobManager process. Access is restricted to files accessible by the JobManager process. All users should upgrade to Flink 1.11.3 or 1.12.0 if their Flink instance(s) are exposed. The issue was fixed in commit b561010b0ee741543c3953306037f00d7a9f0801 from apache/flink:master.
9.1
97.9%
Vector breakdown
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
- Published
- Jan 5, 2021
- Modified
- Oct 21, 2025
- Added to KEV
- May 23, 2024
- Federal patch due
- Jun 13, 2024
CISA required action
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Weakness classification
Proof-of-concept & exploitation references
Weaponization
Public repositories whose name or description references CVE-2020-17519, found via a live GitHub search at request time. These are community-sourced signals, not a verified working exploit - cross-check each one before relying on it, and treat higher star counts and recent activity as (weak) corroboration, not proof.
No public GitHub repositories referencing CVE-2020-17519 were found at last check. Absence here is not proof no exploit exists - see the references below for vendor advisories and write-ups.
References
Frequently asked questions
What is CVE-2020-17519?
A change introduced in Apache Flink 1.11.0 (and released in 1.11.1 and 1.11.2 as well) allows attackers to read any file on the local filesystem of the JobManager through the REST interface of the JobManager process. Access is restricted to files accessible by the JobManager process. All users should upgrade to Flink 1.11.3 or 1.12.0 if their Flink instance(s) are exposed. The issue was fixed in commit b561010b0ee741543c3953306037f00d7a9f0801 from apache/flink:master.
How severe is CVE-2020-17519?
CVE-2020-17519 has a CVSS base score of 9.1 out of 10 (CVSS 3.1).
Is CVE-2020-17519 actively exploited in the wild?
Yes. CVE-2020-17519 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added May 23, 2024, meaning CISA has confirmed evidence of active exploitation.
What is the EPSS score for CVE-2020-17519?
97.9% - meaning FIRST.org's EPSS model estimates a 97.9% probability this vulnerability will be exploited in the wild within 30 days (100% percentile among all scored CVEs).
Is there exploit tooling available for CVE-2020-17519?
Yes - a public Nuclei template referencing CVE-2020-17519 exist in public repositories we checked.
What type of vulnerability is CVE-2020-17519?
CVE-2020-17519 is classified under CWE-552 (CWE-552 Files or Directories Accessible to External Parties).
Cross-checked against
Impactr finds and proves whether CVE-2020-17519 - or flaws like it - are actually reachable in your own web apps and APIs, with a reproducible exploit as evidence.
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