KEV Intelligence

Vulnerability report

Exploited in the wild Confirmed confidence In CISA KEV

CVE-2020-17519

Apache Flink Path Traversal

Apache Software Foundation / Apache Flink · 1.11.0 to <= 1.11.2

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Severity
CVSS 7.5 · High
Confidence
Confirmed
Exploit status
Exploited in the wild
EPSS
97.9%
First observed
—
Last observed
—

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2020-17519 is an unauthenticated vulnerability affecting 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...

Is it exploited?

Yes. KEV Intelligence tracks this CVE as a known exploited vulnerability. Confidence is confirmed.

Who is affected?

Apache Software Foundation / Apache Flink 1.11.0 to <= 1.11.2.

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

Apache Flink Path Traversal

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.

Vendor Product Affected Status
apache flink Through 1.11.2 Affected
Apache Software Foundation Apache Flink Apache Flink 1.11.0 to 1.11.2 Affected
Published
05 Jan 2021
Exploitation Reported
23 May 2024
Attack vector
Remote
Complexity
Low
Privileges
None
User interaction
None

Tags

cisa apache nessus_scanner nuclei_scanner

CVE References

Exploitation evidence

Why KEV Intelligence marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

CISA

Recorded 23 May 2024

Independent exploitation attestation added to the KEV Intelligence record.

Proof of concept available

GitHub

Recorded 06 Jan 2021

Public scanner or PoC coverage increases practical exploitability.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the KEV Intelligence Pro API.

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Source Added
CISA First 2024-05-23 00:00 UTC
The Shadowserver 2026-06-15 00:00 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets
0
User-Agents
0

Raw values available in Pro and Enterprise.

Virtual patch status

No KEV Intelligence virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

Scanner Artifacts

Scanner and exploit-framework references linked to this CVE.

Scanner Reference Detected
Nuclei https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2020/CVE-2020-17519.yaml 25 Apr 2025
Nessus https://www.tenable.com/plugins/nessus/146314 08 Mar 2023

Risk and context

Severity, weaknesses, and research context

CVSS v3.1

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

EPSS

97.9%

Weaknesses

Files or Directories Accessible to External Parties CWE-552

All CVSS Scores

CVSS v3.1 7.5 High

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

CVSS v2.0 5.0 Medium

AV:N/AC:L/Au:N/C:P/I:N/A:N

Potential Proof of Concepts

These PoCs are unverified and could contain malware. Use at your own risk.

Apache Flink - Local File Inclusion

nuclei · Created Unknown

Timeline

From disclosure to observed exploitation

  1. KEV confirmed by The Shadowserver

    Exploitation attested by an external source

  2. Public PoC available

    Public proof-of-concept code published

  3. Nuclei template available

    Scanner coverage available

  4. Added to CISA KEV

    Listed in the CISA Known Exploited Vulnerabilities catalog

  5. Nessus plugin available

    Scanner coverage available

  6. CVE published

    Vulnerability disclosed publicly

  7. CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2020-17519

Free JSON includes basic KEV fields 
{
  "cve_id": "CVE-2020-17519",
  "confidence": "Confirmed",
  "cvss_score": 7.5,
  "cvss_estimated": false,
  "epss_score": 0.97856,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}

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