CVE-2020-17518

HIGHNVD 7.58.1▲
EchelonGraph scoreHIGH confidence

Score elevated to 8.1 because EPSS predicts 51% probability of exploitation within the next 30 days (98th percentile of EPSS-scored CVEs). NVD baseline CVSS 7.5 retained for reference. Confidence: see factors.

Triggered by: EPSS exploit prediction (continuous uplift above 30%)
Sources: epss, nvd
Elevated
8.1EG
EchelonGraph verdictPatch this weekExploitation is likely or a public exploit exists.
  • High exploitation likelihood — EPSS 51%
CISA-KEV: Not listedEPSS PROB: 51%CVSS: 7.5Exploit: Elevated riskExposed services: Not assessed

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
8.1HIGHhigh confidence
EG Risk
62
EG Risk 62/100CISA SSVC

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
Severity81% × 45%
Exploitation51% × 40%
Automatability30% × 15%
CISA SSVC: Track at low or medium mission impact; Track* or Attend at high (mission-essential systems).
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
51%
EPSS %ILE
98th
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track* or Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (EG-KEV: elevated) · Automatable unknown (not published for this CVE) · Technical impact partial (CVSS below 9.0). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

January 5, 2021

Last Modified

November 21, 2024

References (50)

Vendor Advisories for CVE-2020-17518(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(3)

Vendor / EcosystemFix (by version range) / 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 rangeFix by version rangeDependents
org.apache.flink:flink-runtime—
  • 1.5.1 up to 1.11.3: fixed in 1.11.3
—

Weakness Classification(2)

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

Additional Vendor Advisories

(1)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 6× in last 7d / 24× 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.

Showing the most recent 100 of 116 total refreshes for this CVE.

  1. 2026-10-09 20:04 UTCEPSS rescore
  2. 2026-10-09 19:25 UTCOSV refresh
  3. 2026-10-07 23:44 UTCEPSS rescore
  4. 2026-10-06 15:13 UTCEPSS rescore
  5. 2026-10-05 17:39 UTCEPSS rescore
  6. 2026-10-03 14:22 UTCEPSS rescore
  7. 2026-10-02 16:22 UTCEPSS rescore
  8. 2026-09-30 15:13 UTCEG score recompute▲ 0.10
  9. 2026-09-30 14:59 UTCEPSS rescore
  10. 2026-09-27 13:40 UTCEPSS rescore
  11. 2026-09-26 15:54 UTCEPSS rescore
  12. 2026-09-24 14:00 UTCEPSS rescore
  13. 2026-09-24 14:00 UTCEPSS rescore
  14. 2026-09-22 14:43 UTCEPSS rescore
  15. 2026-09-21 20:28 UTCEPSS rescore
  16. 2026-09-20 02:21 UTCOSV refresh
  17. 2026-09-18 19:23 UTCEPSS rescore
  18. 2026-09-17 19:22 UTCEPSS rescore
  19. 2026-09-17 19:22 UTCEPSS rescore
  20. 2026-09-16 14:04 UTCEPSS rescore
  21. 2026-09-15 03:06 UTCEPSS rescore
  22. 2026-09-15 03:06 UTCEPSS rescore
  23. 2026-09-12 14:56 UTCEPSS rescore
  24. 2026-09-11 14:48 UTCEPSS rescore
  25. 2026-09-10 09:29 UTCEPSS rescore
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  1. 2026-09-08 21:56 UTCEPSS rescore
  2. 2026-09-07 15:57 UTCEPSS rescore
  3. 2026-09-06 13:44 UTCEPSS rescore
  4. 2026-09-05 15:24 UTCEPSS rescore
  5. 2026-09-04 13:57 UTCEPSS rescore
  6. 2026-09-02 14:08 UTCEPSS rescore
  7. 2026-09-01 06:23 UTCOSV refresh
  8. 2026-09-01 03:32 UTCEPSS rescore
  9. 2026-08-30 19:14 UTCEPSS rescore
  10. 2026-08-26 14:42 UTCEPSS rescore
  11. 2026-08-25 13:45 UTCEPSS rescore
  12. 2026-08-21 23:45 UTCEPSS rescore
  13. 2026-08-20 22:52 UTCEPSS rescore
  14. 2026-08-19 17:00 UTCEPSS rescore
  15. 2026-08-18 13:44 UTCEPSS rescore
  16. 2026-08-17 13:43 UTCEPSS rescore
  17. 2026-08-16 14:52 UTCEPSS rescore
  18. 2026-08-16 02:11 UTCEPSS rescore
  19. 2026-08-15 05:37 UTCOSV refresh
  20. 2026-08-15 01:26 UTCEPSS rescore
  21. 2026-08-13 21:57 UTCEPSS rescore
  22. 2026-08-12 13:47 UTCEPSS rescore
  23. 2026-08-09 13:43 UTCEPSS rescore
  24. 2026-08-08 16:33 UTCEPSS rescore
  25. 2026-08-06 13:43 UTCEPSS rescore
  26. 2026-08-02 02:23 UTCEPSS rescore
  27. 2026-07-30 17:51 UTCOSV refresh
  28. 2026-07-30 16:25 UTCEPSS rescore
  29. 2026-07-30 01:27 UTCEPSS rescore
  30. 2026-07-28 15:32 UTCEPSS rescore
  31. 2026-07-26 14:51 UTCEPSS rescore
  32. 2026-07-25 14:15 UTCEPSS rescore
  33. 2026-07-25 14:14 UTCEPSS rescore
  34. 2026-07-24 14:14 UTCEPSS rescore
  35. 2026-07-23 01:50 UTCEG score recompute▲ 0.50
  36. 2026-07-22 22:36 UTCEG score recompute
  37. 2026-07-22 14:05 UTCEPSS rescore
  38. 2026-07-21 15:22 UTCEPSS rescore
  39. 2026-07-21 15:22 UTCEPSS rescore
  40. 2026-07-20 17:04 UTCEPSS rescore
  41. 2026-07-20 17:04 UTCEPSS rescore
  42. 2026-07-19 02:26 UTCEPSS rescore
  43. 2026-07-19 02:26 UTCEPSS rescore
  44. 2026-07-16 16:59 UTCEPSS rescore
  45. 2026-07-15 16:55 UTCEPSS rescore
  46. 2026-07-13 22:27 UTCEPSS rescore
  47. 2026-07-13 22:27 UTCEPSS rescore
  48. 2026-07-13 06:10 UTCEPSS rescore
  49. 2026-07-13 06:10 UTCEPSS rescore
  50. 2026-07-13 03:07 UTCOSV refresh
  51. 2026-07-11 08:25 UTCEPSS rescore
  52. 2026-07-11 08:25 UTCEPSS rescore
  53. 2026-07-09 19:07 UTCEPSS rescore
  54. 2026-07-08 15:12 UTCEPSS rescore
  55. 2026-07-05 02:27 UTCEPSS rescore
  56. 2026-07-01 15:03 UTCEPSS rescore
  57. 2026-06-30 23:20 UTCEPSS rescore
  58. 2026-06-30 23:20 UTCEPSS rescore
  59. 2026-06-29 14:04 UTCEPSS rescore
  60. 2026-06-28 04:54 UTCEPSS rescore
  61. 2026-06-28 04:54 UTCEPSS rescore
  62. 2026-06-27 03:06 UTCEPSS rescore
  63. 2026-06-25 13:47 UTCEPSS rescore
  64. 2026-06-24 14:03 UTCEPSS rescore
  65. 2026-06-24 14:03 UTCEPSS rescore
  66. 2026-06-24 12:48 UTCOSV refresh
  67. 2026-06-23 21:31 UTCEPSS rescore
  68. 2026-06-23 21:31 UTCEPSS rescore
  69. 2026-06-21 14:54 UTCEPSS rescore
  70. 2026-06-21 14:54 UTCEPSS rescore
  71. 2026-06-21 01:57 UTCEPSS rescore
  72. 2026-06-21 01:57 UTCEPSS rescore
  73. 2026-06-18 17:50 UTCEPSS rescore
  74. 2026-06-17 17:50 UTCEPSS rescore
  75. 2026-06-16 17:50 UTCEPSS rescore

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 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 51% probability of exploitation in the next 30 days (98th percentile of EPSS-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 8.1 (HIGH).
How do I remediate CVE-2020-17518?
A fix for CVE-2020-17518 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2020-17518 are linked in the Vendor Advisories panel on this page.

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