CVE-2020-17518

HIGHNVD 7.58.0▲
EchelonGraph scoreHIGH confidence

Score elevated to 8.0 because EPSS predicts 50% probability of exploitation within the next 30 days (top 1.2% of all CVEs). NVD baseline CVSS 7.5 retained for reference. Confidence: see factors.

Triggered by: EPSS exploit prediction ≥85%
Sources: epss, nvd
Elevated
8.0EG
EchelonGraph verdictPatch this weekExploitation is likely or a public exploit exists.
  • High exploitation likelihood — EPSS 50%
CISA-KEV: Not listedEPSS PROB: 50%CVSS: 7.5Exploit: Elevated riskExposed: 0

A fix is available — apply it.

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.

CVSS v3
7.5
EG Score
8.0(high)
EG Risk
61(Track)
EG Risk 61/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity80% × 45%
Exploitation50% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
50%
EPSS %ILE
99%
KEV
Not listed

Published

January 5, 2021

Last Modified

November 21, 2024

References (50)

Patch Availability(3)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatpatch2021-08-18redhat
redhatpatch2021-08-18redhat
redhatflink2021-08-11redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(1 across 1 ecosystem)
Maven(1)
PackageVulnerable rangeFixed inDependents
org.apache.flink:flink-runtime—1.11.3—

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

All Vendor Advisories

(3)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 11× in last 7d / 31× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-26 14:51 UTCEPSS rescore
  2. 2026-07-25 14:15 UTCEPSS rescore
  3. 2026-07-25 14:14 UTCEPSS rescore
  4. 2026-07-24 14:14 UTCEPSS rescore
  5. 2026-07-23 01:50 UTCEG score recompute▲ 0.50
  6. 2026-07-22 22:36 UTCEG score recompute
  7. 2026-07-22 14:05 UTCEPSS rescore
  8. 2026-07-21 15:22 UTCEPSS rescore
  9. 2026-07-21 15:22 UTCEPSS rescore
  10. 2026-07-20 17:04 UTCEPSS rescore
  11. 2026-07-20 17:04 UTCEPSS rescore
  12. 2026-07-19 02:26 UTCEPSS rescore
  13. 2026-07-19 02:26 UTCEPSS rescore
  14. 2026-07-16 16:59 UTCEPSS rescore
  15. 2026-07-15 16:55 UTCEPSS rescore
  16. 2026-07-13 22:27 UTCEPSS rescore
  17. 2026-07-13 22:27 UTCEPSS rescore
  18. 2026-07-13 06:10 UTCEPSS rescore
  19. 2026-07-13 06:10 UTCEPSS rescore
  20. 2026-07-13 03:07 UTCOSV refresh
  21. 2026-07-11 08:25 UTCEPSS rescore
  22. 2026-07-11 08:25 UTCEPSS rescore
  23. 2026-07-09 19:07 UTCEPSS rescore
  24. 2026-07-08 15:12 UTCEPSS rescore
  25. 2026-07-05 02:27 UTCEPSS rescore
Show 36 more
  1. 2026-07-01 15:03 UTCEPSS rescore
  2. 2026-06-30 23:20 UTCEPSS rescore
  3. 2026-06-30 23:20 UTCEPSS rescore
  4. 2026-06-29 14:04 UTCEPSS rescore
  5. 2026-06-28 04:54 UTCEPSS rescore
  6. 2026-06-28 04:54 UTCEPSS rescore
  7. 2026-06-27 03:06 UTCEPSS rescore
  8. 2026-06-25 13:47 UTCEPSS rescore
  9. 2026-06-24 14:03 UTCEPSS rescore
  10. 2026-06-24 14:03 UTCEPSS rescore
  11. 2026-06-24 12:48 UTCOSV refresh
  12. 2026-06-23 21:31 UTCEPSS rescore
  13. 2026-06-23 21:31 UTCEPSS rescore
  14. 2026-06-21 14:54 UTCEPSS rescore
  15. 2026-06-21 14:54 UTCEPSS rescore
  16. 2026-06-21 01:57 UTCEPSS rescore
  17. 2026-06-21 01:57 UTCEPSS rescore
  18. 2026-06-18 17:50 UTCEPSS rescore
  19. 2026-06-17 17:50 UTCEPSS rescore
  20. 2026-06-16 17:50 UTCEPSS rescore
  21. 2026-06-16 17:50 UTCEPSS rescore
  22. 2026-06-15 17:46 UTCEPSS rescore
  23. 2026-06-07 17:16 UTCOSV refresh
  24. 2026-06-05 22:45 UTCEPSS rescore
  25. 2026-06-05 22:45 UTCEPSS rescore
  26. 2026-06-04 13:10 UTCEPSS rescore
  27. 2026-06-04 13:10 UTCEPSS rescore
  28. 2026-06-01 13:50 UTCEPSS rescore
  29. 2026-06-01 13:50 UTCEPSS rescore
  30. 2026-05-31 00:15 UTCEPSS rescore
  31. 2026-05-31 00:15 UTCEPSS rescore
  32. 2026-05-28 13:43 UTCEPSS rescore
  33. 2026-05-28 13:43 UTCEPSS rescore
  34. 2026-05-24 16:48 UTCEPSS rescore
  35. 2026-05-23 07:53 UTCEG score recompute
  36. 2026-05-23 07:53 UTCVendor advisory

Publicly available exploits

(3 references)

Working exploit code is in the public domain (2 GitHub PoCs). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCmurataydemir/CVE-2020-17518
    First seen Jan 10, 2021

    [CVE-2020-17518] Apache Flink RESTful API Arbitrary File Upload via Directory Traversal

    Open source ↗
  • GitHub PoCQmF0c3UK/CVE-2020-17518
    First seen Jan 6, 2021
    Open source ↗
  • Nucleihttp/cves/2020/CVE-2020-17518.yaml
    First seen Jan 1, 2020

    Apache Flink 1.5.1 - Local File Inclusion

    Open source ↗

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2020-17518?
CVE-2020-17518 is a high vulnerability published on January 5, 2021. 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…
When was CVE-2020-17518 disclosed?
CVE-2020-17518 was first published in the National Vulnerability Database on January 5, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2020-17518 actively exploited?
CVE-2020-17518 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 50% probability of exploitation in the next 30 days, which ranks it in the top 1.2% of all scored CVEs.
What is the CVSS score of CVE-2020-17518?
CVE-2020-17518 has a CVSS v3 base score of 7.5 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 8.0.
How do I remediate CVE-2020-17518?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2020-17518, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2020-17518

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