Unauthenticated file read via encoded path traversal
Published Jan 5, 2021 · Updated Oct 21, 2025
Path traversal in Apache Flink 1.11.0 through 1.11.2 allows remote attackers to read JobManager-host files through its REST interface. JobManagerCustomLogHandler uses the untrusted path as a filename under the log directory, allowing a doubly encoded parent-directory sequence to escape that directory. The REST interface must be exposed, and disclosure is limited to files readable by the JobManager process.
Summary
What happened
Path traversal in Apache Flink 1.11.0 through 1.11.2 allows remote attackers to read JobManager-host files through its REST interface. JobManagerCustomLogHandler uses the untrusted path as a filename under the log directory, allowing a doubly encoded parent-directory sequence to escape that directory. The REST interface must be exposed, and disclosure is limited to files readable by the JobManager process.
The record
- CVE
- CVE-2020-17519
- Published
- Jan 5, 2021
- Updated
- Oct 21, 2025
- Vendor
- The Apache Software Foundation
- Product
- Apache Flink
- Classifications
- CWE-552, T1005
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jan 5, 2021CVE publishedPublication date reported by the CVE source.
- May 23, 2024Exploitation reportedCISA Known Exploited Vulnerabilities catalog entry
- Oct 21, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=1.11.0 <=1.11.2
- Affected versionversion=Apache Flink 1.11.0 to 1.11.2
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
View daily counts
| Reporting day | Unique IPs |
|---|---|
| Sep 10, 2026 | 3 |
| Sep 11, 2026 | 1 |
| Sep 12, 2026 | 2 |
| Sep 13, 2026 | 1 |
| Sep 14, 2026 | 3 |
| Sep 15, 2026 | 1 |
| Sep 16, 2026 | 3 |
Weakness, pattern, technique
Public exploit references
- Apache Flink File Read Metasploit modulefunctional · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Reported exploitation
- CISA Known Exploited Vulnerabilities catalog entryknown exploited catalog
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo