CVE-2020-17518

mediumpriority · attend · 57EPSS 0.491 · 99 %ileexploit · PoCEUUS

grimoire priorityP1 · Urgent

Exploitable?

Public exploit

3 exploits · PoC

Likely / severe?

49.1% (99th) EPSS

CVSS 5 · medium

Is it mine?

4 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · osv · nvd

EPSS · scored 2026-10-23

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

Technical severity, 0–10. One row per scoring source.

7.5

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 5–7.5

v2.05mediumAV:N/AC:L/Au:N/C:N/I:P/A:Nprimary · NVD / NIST USexploitability 10 · impact 2.9

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:Nprimary · NVD / NIST USexploitability 3.9 · impact 3.6

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:Nsecondary · OSV

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N/E:Hsecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-22USprimaryCWE-22USCWE-23USCWE-23US

exploits (3)

Public proof-of-concept and weaponised exploit code.

QmF0c3UK/CVE-2020-17518QmF0c3UK/CVE-2020-17518PoC · poc_in_github
murataydemir/CVE-2020-17518[CVE-2020-17518] Apache Flink RESTful API Arbitrary File Upload via Directory TraversalPoC · poc_in_github
rakjong/Flink-CVE-2020-17518-getshell利用Apache Flink CVE-2020-17518 getshellPoC · poc_in_github

affected products (4)

Products and version ranges known to be affected.

Apache Software Foundation Apache Flink≤ Apache Flink 1.5.1 to 1.11.2enisa_euvdEU
apache flink1.5.1 → 1.11.3nvdUScpe:2.3:a:apache:flink:*:*:*:*:*:*:*:*
Bitnami flink1.5.1 → 1.11.3osvUSpkg:bitnami/flink
Maven org.apache.flink:flink-runtime1.5.1 → 1.11.3osvUSpkg:maven/org.apache.flink/flink-runtime

advisories (2)

Vendor and ecosystem advisories describing this.

GHSA-7q5g-gph2-4rc6Upload of file to arbitrary path in Apache Flink2022-02-09ghsa · osvUS
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.
BIT-flink-2020-17518Apache Flink directory traversal attack: remote file writing through the REST API2024-03-06vendor · osvUS
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.

also known as (5)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd osv nvd NVD CVE.org MITRE

published 2021-01-05modified 2026-06-17

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+12475 more

references (78)

External citations — patches, advisories, analysis.

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