Is CVE-2020-17518 being actively exploited?

It is not currently in CISA's KEV catalog. Its EPSS exploitation probability is 52%.

What products does CVE-2020-17518 affect?

Tracked products affected include Flink. Check the version you run to see whether it is affected.

How do I fix CVE-2020-17518?

Apply the vendor fix promptly. Upgrade affected products to a fixed version.

CVE-2020-17518

Q: What is CVE-2020-17518?

CVE-2020-17518 is a high-severity software vulnerability (Path traversal) with a CVSS score of 7.5. 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 Fli

HIGH severity · CVSS 7.5 · Path traversal

7.5CVSS HIGH

Summary

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.

Impact & exploitability

Attack vectorNetwork

Attack complexityLow

Privileges requiredNone

User interactionNone

Confidentiality impactNone

Integrity impactHigh

Availability impactNone

Exploit probability (EPSS)52%

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

Affected products we track (1)

Flink

Recommendation

Apply the vendor fix promptly. Open any affected product above for its exact safe version.

Additional information

NVD record
http://www.openwall.com/lists/oss-security/2021/01/05/1Advisory
https://lists.apache.org/thread.html/r0b000dc028616d33cb9aa388eb45d516b789cab0024dad94bc06588a%40%3Cissues.flink.apache.org%3E
https://lists.apache.org/thread.html/r1125f3044a0946d1e7e6f125a6170b58d413ebd4a95157e4608041c7%40%3Cannounce.apache.org%3E
https://lists.apache.org/thread.html/r229167538863518738e02f4c1c5a8bb34c1d45dadcc97adf6676b0c1%40%3Cdev.flink.apache.org%3E
https://lists.apache.org/thread.html/r26fcdd4fe288323006253437ebc4dd6fdfadfb5e93465a0e4f68420d%40%3Cuser-zh.flink.apache.org%3E
https://lists.apache.org/thread.html/r28f17e564950d663e68cc6fe75756012dda62ac623766bb9bc5e7034%40%3Cissues.flink.apache.org%3E
https://lists.apache.org/thread.html/r4a87837518804b31eb9db3048347ed2bb7b46fbaad5844f22a9fd4dc%40%3Cissues.flink.apache.org%3E
https://lists.apache.org/thread.html/r5444acac3407ef6397d6aef1b5aec2db53b4b88ef221e63084c1e5f2%40%3Cissues.flink.apache.org%3E