vciy

CVE-2020-17518

INDEX BUILT · 2026-09-20

No source can show you its own past. This one can.

Print this page to keep the view as it stands on this date. Everything hidden behind a disclosure opens, and every receipt prints with its value.

Apache Flink directory traversal attack: remote file writing through the REST API

CVE-2020-175184 of 4 sources documented this
44

rank 44 = 23 + 19 + 0 + 2 + 0

rank@v1 · scheduled

Someone is already using it

CISA KEV catalog · public proof-of-concept · FIRST EPSS

EPSS 0.50038  ·  without this subject the record ranks 21

What it costs you if it fires

NVD CVSS base score, then the CNA's own

CVSS 7.5, from NVD  ·  without this subject the record ranks 25

It is getting worse, not staying still

FIRST EPSS series, rescorings and bad loads removed

no persisting rise in 365 days  ·  without this subject the record ranks 44

How much of the world it touches

NVD CPE configurations

1 product in the CPE ranges  ·  without this subject the record ranks 42

Someone else already set the date

CISA KEV remediation due date

no CISA due date  ·  without this subject the record ranks 44

Unaudited dollar value2 of 3 inputs carry a receipt
Exposure$1.53Mover the next 30 days, if this record is yours
Movement+$605,000on 2024-12-17, the last material move, 1 year, 6 months before this reading
Basisassumeda published average, not your estate

$1.53M = $4.99M incident cost x 0.6121449559255632 exposure x 0.50038 likelihood

udv@v1 · unaudited · wrong for you until you say what you run

$4.99M is the cost of a breach that happened, from IBM Cost of a Data Breach Report 2026, global average. It is not the value of any asset of yours. That average already covers breaches of every severity, so scaling it by exposure understates a partial-impact record. That is an assumption, not a measurement. Your own asset value goes in the decision record.

Hindsight · the state

0.50038EPSSNOT IN KEVas of 2026-09-20
Severity7.5 HIGHreceipt
Harmunauthenticated · networkreceipt
Exploitationpublic proof-of-conceptreceipt
Defenseunaffected versions publishedreceipt
Movementsteadyreceipt
STEADY10Holding near 0.50 across 46 observations. arc-rules@v1

Foresight · where to check next

Cloud ConfigCVE-2021-40870JetBrainsFortinet FortiWebTrend Micro, Inc.17518

This record is one instance of CWE-23, relative path traversal. The index holds 513 prior instances of this class, 5 KEV-listed. The nearest of its KEV-listed records are drawn beside this. taxonomy@v1

Full pattern panel

Prior records in this weakness class. Each is its own record, dated and receipted.
Color is a claim, not decoration:the hostile worldthe defenseno signalspoke length is how much of the record matches, not how bad it is

Running Apache Flink? Check your version

A deterministic range check against the ranges this record publishes. It tells you where a version sits in the record, not whether your deployment is exploitable. No account needed.

Watch this record

Matches your own product list against every record this index holds, and tells you when one of them moves.

What counts as a move

Set up a watchlist (needs a Practitioner account)

Record your call

Keep your verdict, your reason and the evidence together. The record takes its date when you save it.

AcceptDeferPatch by…Not affectedMitigated

Choose your verdict, then sign in or use an email link. Your first 100 records are free. Evidence is frozen when the record is created.

Private to your organization unless you share it. Put the proof link in your ticket so a reviewer can inspect the basis for your call. See how decision records work.

Harm, if it fires from the vector and the weakness

Written for the ticket you're about to file.

Reachnetwork-reachable · no privileges required · no user interaction · low attack complexityreceipt
ImpactComplete integrity lossreceipt
Scored fromCVSS v3.1 · NVD's vectorreceipt
Weakness classCWE-23 Relative Path Traversalreceipt
Published consequencesCWE-23: Integrity, Confidentiality, Availability: Execute Unauthorized Code or Commands; Integrity: Modify Files or Directories; Confidentiality: Read Files or Directories…[email protected]

CISA KEV & Federal Remediation Deadline from the record and CISA

The fix, and how long it's been waiting.

First unaffected version, by branchflink 1.11.3receipt
Patch available sinceNo dated patch-availability record in held sources. The index holds reference URLs without dates and only the current revision of the CVE record, so the day a fix first existed cannot be derived. Only the versions it landed in.

Exploit Status & Known PoCs a ladder, not a score

Current rung: Proof-of-concept published · 3 public repositories, 2021-01-06.

  • RUNG 1Nothing observed in held sources
  • RUNG 2Proof-of-concept published · 3 public repositories2021-01-06receipt
  • RUNG 3Exploited in the wild · CISA KEV listed
  • RUNG 4Ransomware campaign use known

Authority who says so

CVSS, NVD7.5 HIGHreceipt
Exploit probability0.50038 · top 1% of all CVEsreceipt
Blast breadth1 product across 1 vendorderived
Assigned byapachereceipt
Recorded changes49 · last 19 Sep 2026derived

Affected & Fixed Versions as published

Affected productApache Software Foundation Apache Flinkreceipt
Published rangesapache flink >= 1.5.1 < 1.11.3receipt

A rung lights from a row in the index, never from an assessment. "Held sources" is the true scope of the claim: this index reads the CVE record, NVD, CISA KEV, FIRST's EPSS and public proof-of-concept repositories, and it does not observe attacks.

Did this affect your environment?Answering needs an account.

What it is stated by the CNA

Apache Flink 1.5.1 introduced a REST handler that allows you to write an uploaded file to an arbitrary location on the local file system, through a maliciously modified HTTP HEADER. The files can be written to any location accessible by Flink 1.5.1. 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 a5264a6f41524afe8ceadf1d8ddc8c80f323ebc4 from apache/flink:master. receipt

NVD's analysis a second authority

severity
7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
weakness
CWE-23; CWE-22
affected versions
apache flink >= 1.5.1 < 1.11.3

check it yourself lists.apache.org lists.apache.org lists.apache.org openwall.com lists.apache.org lists.apache.org +14 morereceipt

Dated events

2022-02-04EPSS moved 0.43 to 0.342023-03-07EPSS moved 0.34 to 0.972026-06-15EPSS moved 0.94 to 0.52

Movement the material steps

14 Apr 20210.42746
7 Mar 20230.97457 · crossed 0.50 and 0.90 · scoring model v2023.03.01
8 Nov 20230.84580 · crossed 0.90
22 Sep 20240.68302
17 Dec 20240.94887 · crossed 0.90
17 Mar 20250.93201 · scoring model v2025.03.14
15 Jun 20260.52332 · crossed 0.90 · scoring model v2026.06.15
26 Jun 20260.50038
Show all 46 observations
14 Apr 20210.42746
4 Feb 20220.34284
7 Mar 20230.97457
30 Mar 20230.97462
27 Apr 20230.97469
31 Jul 20230.97448
12 Aug 20230.97465
21 Sep 20230.97464
1 Nov 20230.97459
8 Nov 20230.84580
14 Nov 20230.86271
25 Dec 20230.86056
23 Jan 20240.86267
22 Feb 20240.85205
8 Mar 20240.81244
8 Apr 20240.82758
10 Jun 20240.78878
27 Jun 20240.82225
15 Jul 20240.79439
19 Aug 20240.74594
22 Sep 20240.68302
7 Oct 20240.67304
25 Oct 20240.66258
9 Nov 20240.67717
26 Nov 20240.73069
12 Dec 20240.75068
17 Dec 20240.94887
12 Jan 20250.95270
17 Mar 20250.93201
22 Apr 20250.93183
16 Sep 20250.9332
1 Oct 20250.93374
13 Oct 20250.93243
27 Oct 20250.93183
28 Oct 20250.93243
18 Nov 20250.93252
21 Nov 20250.93243
27 Dec 20250.93183
28 Dec 20250.93243
15 Jan 20260.9379
21 Apr 20260.93934
7 May 20260.93976
13 May 20260.93948
3 Jun 20260.93803
15 Jun 20260.52332
26 Jun 20260.50038

46 observations held. A highlighted step crossed a promotion threshold. A step marked with a scoring model moved because the instrument was replaced, not because the vulnerability changed. receipt

The full biography

EPSS 0.50038Published2021-01-05Public PoC2021-01-06Index as of2026-06-26

The record had been public for 5 years, 5 months when this index was last written.

Published 2021-01-05 receipt · Public PoC 2021-01-06 receipt · Index as of 2026-06-26 derived

The pattern, elsewhere

This record is one instance of CWE-23, relative path traversal. The index holds 513 prior instances of this class, 5 KEV-listed. The nearest of its KEV-listed records are drawn beside this. [email protected]

CVE-2020-5410 · Spring Cloud Configmatches 7 of 10KEV listed · 2020receipt
CVE-2021-40870matches 6 of 9KEV listed · 2021receipt
CVE-2024-27199 · JetBrains TeamCitymatches 6 of 10KEV listed · 2024receipt
CVE-2025-64446 · Fortinet FortiWebmatches 6 of 10KEV listed · 2025receipt
CVE-2026-34926 · Trend Micro, Inc. TrendAI Apex Onematches 1 of 10KEV listed · 2026receipt

"Matches n of m" counts the attributes the two records can both be compared on: the CVSS metrics they share a version of, any weakness class beyond this one, and the vendor. fit-rules@v1

513 records in this class held. The six above are drawn from the ones CISA has listed as exploited, ranked by how much of the record matches this one. That is why every one of them is KEV-listed: the pool is, so the colour on those spokes says nothing the pool has not already said.

No curated product neighbourhood is held for this product, so the records above are the nearest this index can name. The neighbourhood table covers a small set of products and is extended by hand.

Siblings and hubs

Records related to this one

Browse the index from here

These are index-wide views, not findings about CVE-2020-17518.

What usually comes next

Everything above needs no account. What is below is work: assembling it, scoping it to your estate, watching it, and handing it to someone else.

Everything on this page is free. Public data. Withholding it protects nothing.