Threats / Apache / CVE-2020-17519
CVE-2020-17519
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-09-19
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 · 2024-05-235EPSS 0.97809 (verify live)6Exploit Public PoC7CVSS 9.1 (CISA)4CISA SSVC Exploitation: active · Automatable: yes · Impact: partial4
01
Is it exploitable?
— the evidence, ranked above the scoreExploit 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
790 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).
Probability (EPSS)
EPSS 0.97809 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
CVSS 9.1 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H) · Affected: Apache, Flink. Confirm exact fixed builds in the vendor advisory.CVSS — CISA-assigned via the ADP container (CVE.org), version 3.1; the CNA left no metrics, so CISA's own score is used ahead of NVD.
Weakness (CWE)
Mapped to CWE-552 Files Accessible to External Parties — weakness family: Path traversal / file.CWE — CNA-assigned (CVE.org); the weakness class drives how the flaw is exploited.
CISA SSVC (triage disposition)
Exploitation: active · Automatable: yes · Technical Impact: partialCISA's own stakeholder-specific triage inputs, published in the CVE record (CISA Coordinator role). NOTE: this is CISA's three decision points; the final Act/Attend/Track decision also requires a Mission & Well-being input not published here, so no overall decision is asserted.
Currency of the record
CISA added this to its KEV catalog 1234 days after the CVE record was published.KEV lag = CISA-KEV dateAdded − CVE.org datePublished; a floor on how long the known-exploited flaw sat in the public record before the federal catalog listed it. Severity/weakness here is CNA- or CISA-assigned (current at disclosure), independent of NVD's analysis backlog.
Public exploit available
Public exploit tooling is catalogued for this CVE (a public proof-of-concept / detection template). Catalog entries: Metasploit module, nuclei template. We link the catalog page(s) only — no payload or code is hosted or restated here.Link, never host — the catalog page is the source; basicsecurity.net does not redistribute payloads.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution 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 board1
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’tEstablished (cited)
Coverage gaps — stated, not hidden
Disclosure & credit2
Catalogued by apacheCNA
Credited with finding it0rich1 of Ant Security FG Labunspecified
Found an error? Propose a correction.
A correction is a cited counter-claim — it must cite a source,
gets reviewed by a second human, and is never auto-applied. See the
correction convention and our identity
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