CVE-2020-17519

HIGH KEV NUCLEI LAB

Apache Flink JobManager Traversal

Title source: metasploit
STIX 2.1

Exploitation Summary

CVE-2020-17519 is actively exploited and listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added May 23, 2024. EIP tracks 16 public exploits from researchers including SunCSR Team, MrCl0wnLab, B1anda0, including a Metasploit module auxiliary/scanner/http/apache_flink_jobmanager_traversal. A Nuclei detection template is also available.

AI-analyzed exploit summary This Metasploit module exploits an unauthenticated directory traversal vulnerability in Apache Flink, allowing arbitrary file read with web server privileges. It sends a crafted GET request to traverse directories and read the specified file.

Description

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.

Exploits (16)

exploitdb WORKING POC VERIFIED
by SunCSR Team · rubywebappsjava
https://www.exploit-db.com/exploits/49398

This Metasploit module exploits an unauthenticated directory traversal vulnerability in Apache Flink, allowing arbitrary file read with web server privileges. It sends a crafted GET request to traverse directories and read the specified file.

Classification
Working Poc 100%
Attack Type
Info Leak
Complexity
Trivial
Reliability
Reliable
Target: Apache Flink 1.11.0, 1.11.1, 1.11.2
No auth needed
Prerequisites: Network access to the target Apache Flink instance
devstral-2 · analyzed Feb 16, 2026 Full analysis →
nomisec SCANNER 61 stars
by MrCl0wnLab · infoleak
https://github.com/MrCl0wnLab/SimplesApachePathTraversal

This repository contains a Python-based scanner for detecting Apache path traversal vulnerabilities, specifically CVE-2020-17519, CVE-2021-41773, and CVE-2021-42013. It includes modules for handling requests, threading, and file operations to test multiple targets efficiently.

Classification
Scanner 90%
Attack Type
Info Leak
Complexity
Moderate
Reliability
Reliable
Target: Apache HTTP Server
No auth needed
Prerequisites: List of target IPs or ranges · Network access to target systems
devstral-2 · analyzed Feb 16, 2026 Full analysis →
nomisec WORKING POC 48 stars
by B1anda0 · infoleak
https://github.com/B1anda0/CVE-2020-17519

This is a Python-based proof-of-concept for CVE-2020-17519, an Apache Flink directory traversal vulnerability. It checks for the presence of the vulnerability by attempting to read /etc/passwd via a crafted URL path.

Classification
Working Poc 95%
Attack Type
Info Leak
Complexity
Trivial
Reliability
Reliable
Target: Apache Flink 1.11.0-1.11.2
No auth needed
Prerequisites: Target URL list in a text file
devstral-2 · analyzed Feb 16, 2026 Full analysis →
nomisec WORKING POC 8 stars
by murataydemir · infoleak
https://github.com/murataydemir/CVE-2020-17519

This repository provides a detailed proof-of-concept for CVE-2020-17519, an arbitrary file read vulnerability in Apache Flink's RESTful API. The exploit leverages path traversal via a maliciously crafted GET request to read sensitive files on the JobManager's filesystem.

Classification
Working Poc 100%
Attack Type
Info Leak
Complexity
Trivial
Reliability
Reliable
Target: Apache Flink versions 1.11.0 to 1.11.2
No auth needed
Prerequisites: Network access to the vulnerable Apache Flink JobManager REST API (typically port 8081)
devstral-2 · analyzed Feb 16, 2026 Full analysis →
nomisec SCANNER 1 stars
by givemefivw · infoleak
https://github.com/givemefivw/CVE-2020-17519

This repository provides a Cheetah language-based scanner for CVE-2020-17519, designed for batch scanning. It requires an IP list file and integration with the Wker main program for execution.

Classification
Scanner 80%
Attack Type
Other
Complexity
Moderate
Reliability
Theoretical
Target: Apache Flink
No auth needed
Prerequisites: List of target IPs in ip.txt · Wker main program
devstral-2 · analyzed Feb 16, 2026 Full analysis →
nomisec WORKING POC 1 stars
by yaunsky · infoleak
https://github.com/yaunsky/CVE-2020-17519-Apache-Flink

This PoC exploits CVE-2020-17519, a directory traversal vulnerability in Apache Flink, allowing arbitrary file read via path traversal in the `/jobmanager/logs` endpoint. The script sends a crafted HTTP request to read `/etc/passwd` and checks for the presence of 'root' in the response.

Classification
Working Poc 95%
Attack Type
Info Leak
Complexity
Trivial
Reliability
Reliable
Target: Apache Flink 1.5.1 to 1.11.2
No auth needed
Prerequisites: Network access to the Flink JobManager web interface
devstral-2 · analyzed Feb 16, 2026 Full analysis →
nomisec WORKING POC 1 stars
by QmF0c3UK · infoleak
https://github.com/QmF0c3UK/CVE-2020-17519

This PoC exploits CVE-2020-17519, a directory traversal vulnerability in Apache Flink's REST API, allowing unauthorized file reads. It uses a crafted URI with multiple encoded traversal sequences to access arbitrary files on the target system.

Classification
Working Poc 95%
Attack Type
Info Leak
Complexity
Trivial
Reliability
Reliable
Target: Apache Flink 1.11.0-1.11.2
No auth needed
Prerequisites: Network access to the Flink JobManager REST API
devstral-2 · analyzed Feb 16, 2026 Full analysis →
nomisec WRITEUP
by shoucheng3 · poc
https://github.com/shoucheng3/apache__flink_CVE-2020-17519_1-11-2

This repository appears to be a fork of Apache Flink with documentation and build scripts, but no actual exploit code for CVE-2020-17519 is present in the provided files. The README and documentation focus on building and contributing to Apache Flink rather than demonstrating the vulnerability.

Classification
Writeup 90%
Attack Type
Other
Complexity
N/a
Reliability
N/a
Target: Apache Flink
No auth needed
devstral-2 · analyzed Feb 16, 2026 Full analysis →
nomisec WORKING POC
by dev-team-12x · poc
https://github.com/dev-team-12x/CVE-2020-17519

This is a Metasploit auxiliary module that exploits an unauthenticated directory traversal vulnerability in Apache Flink versions 1.11.0, 1.11.1, and 1.11.2, allowing arbitrary file read with web server privileges. The module sends a crafted HTTP GET request with traversal sequences to read sensitive files like /etc/passwd.

Classification
Working Poc 100%
Attack Type
Info Leak
Complexity
Trivial
Reliability
Reliable
Target: Apache Flink 1.11.0, 1.11.1, 1.11.2
No auth needed
Prerequisites: Network access to the Apache Flink web interface · Target running a vulnerable version of Apache Flink
devstral-2 · analyzed Feb 16, 2026 Full analysis →
nomisec WORKING POC
by GazettEl · poc
https://github.com/GazettEl/CVE-2020-17519

This is a Python-based directory traversal exploit for CVE-2020-17519, targeting Apache Flink's JobManager logs endpoint. It allows attackers to read arbitrary files on the server by manipulating traversal sequences and supports multi-threading, proxy usage, and response saving.

Classification
Working Poc 95%
Attack Type
Info Leak
Complexity
Moderate
Reliability
Reliable
Target: Apache Flink (JobManager logs endpoint)
No auth needed
Prerequisites: Network access to the target Apache Flink instance · Knowledge of file paths to traverse
devstral-2 · analyzed Feb 16, 2026 Full analysis →
nomisec WORKING POC
by zhangweijie11 · infoleak
https://github.com/zhangweijie11/CVE-2020-17519

This PoC exploits a directory traversal vulnerability in Apache Flink (CVE-2020-17519) by crafting a URL with encoded traversal sequences to access the /etc/passwd file. It sends an HTTP GET request and checks for the presence of 'root:x' in the response to confirm vulnerability.

Classification
Working Poc 95%
Attack Type
Info Leak
Complexity
Trivial
Reliability
Reliable
Target: Apache Flink (versions before 1.11.3 and 1.12.0)
No auth needed
Prerequisites: Target Apache Flink instance with exposed jobmanager endpoint
devstral-2 · analyzed Feb 16, 2026 Full analysis →
nomisec SCANNER
by Osyanina · poc
https://github.com/Osyanina/westone-CVE-2020-17519-scanner

This repository provides a scanner for CVE-2020-17519, which affects Apache Flink versions 1.11.0, 1.11.1, and 1.11.2. The vulnerability allows attackers to read/write remote files via REST API.

Classification
Scanner 80%
Attack Type
Info Leak
Complexity
Trivial
Reliability
Reliable
Target: Apache Flink 1.11.0, 1.11.1, 1.11.2
No auth needed
Prerequisites: Network access to the target's REST API
devstral-2 · analyzed Feb 16, 2026 Full analysis →
nomisec WORKING POC
by radbsie · infoleak
https://github.com/radbsie/CVE-2020-17519-Exp

This Go-based exploit targets CVE-2020-17519, a directory traversal vulnerability in Apache Flink's REST API. It attempts to read /etc/passwd via path traversal sequences and checks for common system user entries to confirm exploitation.

Classification
Working Poc 95%
Attack Type
Info Leak
Complexity
Trivial
Reliability
Reliable
Target: Apache Flink (versions before 1.11.3 and 1.12.0)
No auth needed
Prerequisites: Network access to the Flink REST API endpoint
devstral-2 · analyzed Feb 16, 2026 Full analysis →
vulncheck_xdb WORKING POC
infoleak
https://github.com/hoanx4/CVE-2020-17519

This repository contains a functional Metasploit auxiliary module that exploits an unauthenticated directory traversal vulnerability in Apache Flink versions 1.11.0, 1.11.1, and 1.11.2, allowing arbitrary file read with web server privileges. The exploit uses URL-encoded traversal sequences to bypass path sanitization and retrieve sensitive files like /etc/passwd.

Classification
Working Poc 100%
Attack Type
Info Leak
Complexity
Trivial
Reliability
Reliable
Target: Apache Flink 1.11.0, 1.11.1, 1.11.2
No auth needed
Prerequisites: Network access to the Apache Flink web interface (default port 8080)
devstral-2 · analyzed Feb 25, 2026 Full analysis →
metasploit WORKING POC
by 0rich1 - Ant Security FG Lab, Hoa Nguyen - Suncsr Team, bcoles · rubypoc
https://github.com/rapid7/metasploit-framework/blob/master/modules/auxiliary/scanner/http/apache_flink_jobmanager_traversal.rb

This Metasploit module exploits an unauthenticated directory traversal vulnerability in Apache Flink's JobManager REST API, allowing arbitrary file retrieval. It validates the target version and retrieves specified files via path traversal.

Classification
Working Poc 100%
Attack Type
Info Leak
Complexity
Trivial
Reliability
Reliable
Target: Apache Flink 1.11.0 to 1.11.2
No auth needed
Prerequisites: Network access to the target's JobManager REST API (default port 8081)
devstral-2 · analyzed Feb 16, 2026 Full analysis →

Nuclei Templates (1)

Apache Flink - Local File Inclusion
HIGHby pdteam

References (17)

Core 17
Core References
Mailing List, Third Party Advisory mailing-list x_refsource_mlist
http://www.openwall.com/lists/oss-security/2021/01/05/2

Scores

CVSS v3 7.5
EPSS 0.9434
EPSS Percentile 100.0%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CISA SSVC

Vulnrichment
Exploitation active
Automatable yes
Technical Impact partial

Lab Environment

COMMUNITY
Community Lab
docker pull sequenceiq/kerberos
docker pull flink/docker-mesos-cluster:latest
+12 more repos

Details

CISA KEV 2024-05-23
VulnCheck KEV 2021-04-12
InTheWild.io 2024-05-17
ENISA EUVD EUVD-2021-0481
CWE
CWE-552
Status published
Products (3)
apache/flink 1.11.0 - 1.11.3
org.apache.flink/flink-runtime_2.11 1.11.0 - 1.11.3Maven
org.apache.flink/flink-runtime_2.12 1.11.0 - 1.11.3Maven
Published Jan 05, 2021
KEV Added May 23, 2024
Tracked Since Feb 18, 2026