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NVD / CVE Program· CNA apache

CVE-2020-17519: Apache Flink directory traversal attack: reading remote files through the REST API

Noroxi assessment

Priority: Now (action score 89/100)

  • CISA has confirmed exploitation in the wild (May 23, 2024). Remediation deadline for US federal agencies: Jun 13, 2024.
  • A ready-made attack module is public (Metasploit, Nuclei); exploiting it takes no special expertise.
  • Probability of exploitation in the next 30 days: 98% (FIRST EPSS); higher than 99.9% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: org.apache.flink:flink-runtime_2.11 (Maven) 1.11.3; org.apache.flink:flink-runtime_2.12 (Maven) 1.11.3.

Patch today or shut off access. Upgrade to org.apache.flink:flink-runtime_2.11 (Maven) 1.11.3; org.apache.flink:flink-runtime_2.12 (Maven) 1.11.3 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · CISA KEV · FIRST EPSS

A change introduced in Apache Flink 1.11.0 (and released in 1.11.1 and 1.11.2 as well) allows attackers to read any file on the local filesystem of the JobManager through the REST interface of the JobManager process. Access is restricted to files accessible by the JobManager process. 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 b561010b0ee741543c3953306037f00d7a9f0801 from apache/flink:master.

HighCVSS 7.5 · v3.1KEVWeaponized Fix available
Published
Jan 5, 2021
Updated
Jun 16, 2026
EPSS
98.0% · 99th percentile

Report tools

JSON

Action score

89

Now

Patch today or shut off access.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
30 / 30 · Listed
EPSS
29 / 30 · 98.0%

CISA SSVC decision

Exploitation
active
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Actively exploited in the wild

CISA added this to its Known Exploited Vulnerabilities catalog on May 23, 2024. That signals real attacks, not theory.

Remediation deadline for US federal agencies: Jun 13, 2024.

Get told when this record changes

  • In CISA KEV: exploitation in the wild confirmed
  • Weaponized exploit exists
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
apacheflink

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • apache flink1.11.0 and later · before 1.11.3

Versions reported by the vendor

Affected version ranges reported by the assigning authority (apache). Independent of NVD's CPE analysis and usually ahead of it.

  • Apache Software Foundation Apache Flink

    • Apache Flink 1.11.0 to 1.11.2affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Mavenorg.apache.flink:flink-runtime_2.11from 1.11.0 · before 1.11.31.11.3
Mavenorg.apache.flink:flink-runtime_2.12from 1.11.0 · before 1.11.31.11.3

Same product

apache: all records

Other highest-scoring records for the same primary product.

  • CVE-2020-17518Apache Flink directory traversal attack: remote file writing through the REST API
    45Plan
  • CVE-2026-35194Apache Flink: Remote code execution via SQL injection in code generation
    32Monitor
  • CVE-2020-1960A vulnerability in Apache Flink (1.1.0 to 1.1.5, 1.2.0 to 1.2.1, 1.3.0 to 1.3.3, 1.4.0 to 1.4.2, 1.5.0 to 1.5.6, 1.6.0 to 1.6.4, 1.7.0 to 1.
    18Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Maven:org.apache.flink:flink-runtime_2.111.11.3Package registry (OSV)
Maven:org.apache.flink:flink-runtime_2.121.11.3Package registry (OSV)

Exploit status

Weaponized

A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.

Evidence

  • Metasploit module ×1
  • Exploit-DB entry ×1
  • Nuclei detection template ×1
  • Proof-of-concept repository on GitHub ×14

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Exploit-DB entrywebapps2021-01-08
Metasploit moduleauxiliary/scanner/http/apache_flink_jobmanager_traversalApache Flink JobManager Traversalauxiliary2021-01-05
Nuclei detection templateNuclei template CVE-2020-17519 —
Proof-of-concept repository on GitHubstars:472021-01-06
Proof-of-concept repository on GitHubstars:12021-01-06
Proof-of-concept repository on GitHubstars:32021-01-06
Proof-of-concept repository on GitHubstars:02021-01-08
Proof-of-concept repository on GitHubstars:82021-01-10
Proof-of-concept repository on GitHubstars:02021-01-14
Proof-of-concept repository on GitHubstars:12021-01-18
Proof-of-concept repository on GitHubstars:02021-02-25
Proof-of-concept repository on GitHubstars:12021-04-13

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Metasploitsame day
  2. Published
  3. First PoC+1 d
  4. CISA KEV+1234 d
  5. TodayNov 3, 2026+2128 d

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
none
Availability
none
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
None
Availability impact
None

Weakness class (CWE)

CWE-552 · Files or Directories Accessible to External Parties

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (15 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records