Path Traversal in Apache Flink

CVE-2020-17518

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.

EPSS: 0.500 (98.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2020-17518?
CVE-2020-17518 is a high-severity vulnerability in Apache Flink, classified under Relative Path Traversal. CVSS score: 7.5/10. Published 2021-01-05.
How severe is CVE-2020-17518?
High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2020-17518 known to be exploited?
58 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.