# Apache Flink Improper Access Control · pwn.watch

> Apache Flink contains an improper access control vulnerability that allows an attacker to read any file on the local filesystem of the JobManager through its REST interface. Added to the CISA KEV catalog on 2024-05-23. CVE-2020-17519 was assigned before 2024; the KEV listing came in 2024.

Page: https://pwn.watch/i/apache-flink-cve-2020-17519 · generated 2026-10-23T03:01:01.167Z

## Status
- Severity: critical · status: closed · patch: patched
- Product: Apache Flink
- Started: 2024-05-23 · closed: 2024-05-23
- CVEs: CVE-2020-17519
- Affected: See vendor advisory (versions are not listed in the KEV record)
- Fixed in: See vendor advisory linked in sources

## Follow this incident
- RSS (one item per update): https://pwn.watch/i/apache-flink-cve-2020-17519/feed.xml
- JSON Feed: https://pwn.watch/i/apache-flink-cve-2020-17519/feed.json
- Full data (timeline, sources, posts, agentBrief): https://pwn.watch/i/apache-flink-cve-2020-17519.json
- This file: https://pwn.watch/i/apache-flink-cve-2020-17519/llms.txt

## Updates (newest first)
- 2024-05-23: CISA added CVE-2020-17519 to the KEV catalog (federal deadline 2024-06-13) (https://www.cisa.gov/known-exploited-vulnerabilities-catalog)

## Fix brief
# Security brief: Apache Flink Improper Access Control

Source: https://pwn.watch/i/apache-flink-cve-2020-17519 · status: closed (closed May 23, 2024) · severity: critical · updated May 23, 2024

## Patch status
**PATCHED: fixed releases exist. Upgrade to a fixed version.**

## What it is
Apache Flink contains an improper access control vulnerability that allows an attacker to read any file on the local filesystem of the JobManager through its REST interface. Added to the CISA KEV catalog on 2024-05-23. CVE-2020-17519 was assigned before 2024; the KEV listing came in 2024.

Severity detail: CVSS 9.1 (v3.1, CISA-ADP), actively exploited (CISA KEV)

- Product: Apache Flink
- CVE / advisory ids: CVE-2020-17519

## Affected versions
- See vendor advisory (versions are not listed in the KEV record)

## Check whether you're affected
No generic command applies (the product is a hosted service, appliance or desktop app). Check the installed version in its admin UI / About screen and compare with the versions above.

## Fix
Upgrade to one of these fixed versions (or later on the same branch):
- See vendor advisory linked in sources

After upgrading, re-run the checks above and redeploy/restart the affected services.

## Latest updates
- May 23, 2024: CISA added CVE-2020-17519 to the KEV catalog (federal deadline 2024-06-13)

## Advisories
- [Apache advisory: CVE-2020-17519](https://lists.apache.org/thread/typ0h03zyfrzjqlnb7plh64df1g2383d) (Apache)
- [NVD: CVE-2020-17519](https://nvd.nist.gov/vuln/detail/CVE-2020-17519) (NVD)
- [CISA Known Exploited Vulnerabilities Catalog](https://www.cisa.gov/known-exploited-vulnerabilities-catalog) (CISA)

## Caveats
Derived from the CISA KEV JSON feed (catalogVersion 2026.10.21); CVSS from the CVE record (cveawg.mitre.org). startedAt is the CVE publication date when it fell in 2024 before the KEV listing, else the KEV dateAdded; exploitation may have begun earlier. closedAt is the KEV listing date (a fix or mitigation was available then unless noted).

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Machine-readable: https://pwn.watch/i/apache-flink-cve-2020-17519.json · all incidents: https://pwn.watch/incidents.json. Verify against the vendor advisory before changing production systems.