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Threats / Apache / CVE-2020-17519
CVE-2020-17519 · EUVD no mirror located · GCVE no mirror located Verified 2026-06-22

Apache Flink vulnerability

Apache Flink REST interface allows unauthenticated local file read on JobManager due to improper access control, enabling information disclosure.

Verdict

Today item — known-exploited.

An attacker can read arbitrary files from the JobManager filesystem via the REST API without authentication. This exposes sensitive configuration, credentials, and application data. The vulnerability is actively exploited in the wild with high EPSS score.

CISA KEV Yes · 2024-05-233EPSS 0.97856 (verify live)4Exploit Public PoC5
01

Is it exploitable?

— the evidence, ranked above the score
Exploit available
Public proof-of-concept exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
709 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2024-05-23).
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.97856 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Apache, Flink. Confirm exact fixed builds in the vendor advisory.
NVD ↗Reported
Weakness (CWE)
Mapped to CWE-552 Files Accessible to External Parties — weakness family: Path traversal / file.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
NVD ↗Reported
02

Who’s exploiting it?

— attribution turns risk into urgency
Attribution not established

No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.

03

Why it matters

— the attack path, told twice: adversary, then board
1

Front door — unauthenticated access narrative 1

Attacker
I discover the Flink JobManager REST endpoint is accessible without authentication.
Business
Operational security posture is compromised by exposed management interfaces.
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
I craft REST requests to read arbitrary files from the JobManager's local filesystem.
Business
Sensitive data including credentials, keys, and configuration files are exfiltrated.
3

Lateral reach — past segmentation narrative 3

Attacker
I obtain database passwords, API keys, and application secrets stored in configuration files.
Business
Downstream systems and data repositories become vulnerable to lateral compromise.
04

What to do

— defensible action
  • Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05

Coverage & confidence

— what we know, and what we don’t

Established (cited)

  • KEV listing (CISA)
  • EPSS probability (FIRST)
  • Public PoC available (VulnCheck)
  • 709 reported-exploitation source(s)
  • CWE weakness mapping (NVD)
  • Public exploit availability
  • Catalogued by apache (CNA)
  • Named finder/reporter credit (CVE.org)
  • Coverage gaps — stated, not hidden

  • No EUVD / GCVE mirror in feed — single-authority dependency for the identifier.
  • EPSS & exposure are time-varying; verify live at the source.
  • Threat-actor attribution not established from feed data — absence of a name is not absence of compromise.
  • Disclosure & credit2
    Catalogued by apacheCNA