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Status published
High
CVE-2020-17518
Apache Flink directory traversal attack: remote file writing through the REST API
Vulnerability Description
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 Analysis
Refer to official advisory for detailed impact metrics.
Remediation
Ensure systems are updated to the latest vendor-supplied patch levels.
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Credits & Attribution
The following person or organization is credited with identifying this vulnerability, as recorded in the NVD database:
- 0rich1 of Ant Security FG Lab
References
- https://lists.apache.org/thread.html/rb43cd476419a48be89c1339b527a18116f23eec5b6df2b2acbfef261%40%3Cdev.flink.apache.org%3E
- https://lists.apache.org/thread.html/rb43cd476419a48be89c1339b527a18116f23eec5b6df2b2acbfef261%40%3Cdev.flink.apache.org%3E
- https://lists.apache.org/thread.html/rb43cd476419a48be89c1339b527a18116f23eec5b6df2b2acbfef261%40%3Cuser.flink.apache.org%3E
- https://lists.apache.org/thread.html/rb43cd476419a48be89c1339b527a18116f23eec5b6df2b2acbfef261%40%3Cannounce.apache.org%3E
- http://www.openwall.com/lists/oss-security/2021/01/05/1
- https://lists.apache.org/thread.html/r28f17e564950d663e68cc6fe75756012dda62ac623766bb9bc5e7034%40%3Cissues.flink.apache.org%3E
- https://lists.apache.org/thread.html/rd6a1a0e2d73220a65a8f6535bbcd24bb66adb0d046c4a1aa18777cf3%40%3Cdev.flink.apache.org%3E
- https://lists.apache.org/thread.html/r8167f30c4c60a11b8d5be3f55537beeda629be61196e693bde403b36%40%3Cissues.flink.apache.org%3E
- https://lists.apache.org/thread.html/r0b000dc028616d33cb9aa388eb45d516b789cab0024dad94bc06588a%40%3Cissues.flink.apache.org%3E
- https://lists.apache.org/thread.html/r705fb2211b82c9f1f8d2b1d4c823bcbca50402ba09b96608ec657efe%40%3Cissues.flink.apache.org%3E
- https://lists.apache.org/thread.html/r5444acac3407ef6397d6aef1b5aec2db53b4b88ef221e63084c1e5f2%40%3Cissues.flink.apache.org%3E
- https://lists.apache.org/thread.html/r710693b0d3b229c81f485804ea1145b4edda79c9e77d66c39a0a2ff1%40%3Cissues.flink.apache.org%3E
- https://lists.apache.org/thread.html/ra8c96bf3ccb4e491f9ce87ba35f134b4449beb2a38d1ce28fd89001f%40%3Cdev.flink.apache.org%3E
- https://lists.apache.org/thread.html/rfe159ccf496d75813f24c6079c5d33872d83f5a2e39cb32c3aef5a73%40%3Cissues.flink.apache.org%3E
- https://lists.apache.org/thread.html/r7b2ee88c66fc1d0823e66475631f5c3e7f0365204ff0cb094d9f2433%40%3Cissues.flink.apache.org%3E
- https://lists.apache.org/thread.html/rec0d650fbd4ea1a5e1224a347d83a63cb44291c334ad58b8809bc23b%40%3Cissues.flink.apache.org%3E
- https://lists.apache.org/thread.html/rf8812a5703f4a5f1341138baf239258b250875699732cfdf9d55b21d%40%3Cissues.flink.apache.org%3E
- https://lists.apache.org/thread.html/rcb9e8af775f2a3706b69153aefde78f208871649df057c70ce2e24f9%40%3Cissues.flink.apache.org%3E
- https://lists.apache.org/thread.html/r88200d2f0b620c6b4b1585a7171355005c89e678b01d0e71a16c57e7%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/r229167538863518738e02f4c1c5a8bb34c1d45dadcc97adf6676b0c1%40%3Cdev.flink.apache.org%3E
- https://lists.apache.org/thread.html/rd2467344f88bcaf108b8209ca92da8ec393c68174bfb8c27d1e20faa%40%3Cdev.flink.apache.org%3E
- https://lists.apache.org/thread.html/r90890afea72a9571d666820b2fe5942a0a5f86be406fa31da3dd0922%40%3Cannounce.apache.org%3E
- https://lists.apache.org/thread.html/r1125f3044a0946d1e7e6f125a6170b58d413ebd4a95157e4608041c7%40%3Cannounce.apache.org%3E
- https://lists.apache.org/thread.html/r26fcdd4fe288323006253437ebc4dd6fdfadfb5e93465a0e4f68420d%40%3Cuser-zh.flink.apache.org%3E
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Affected Vendor
Apache Software Foundation
View all reports →Affected Software
Apache Flink
Vulnerable Versions:
Apache Flink 1.5.1 to 1.11.2
Timeline
Official Publish:
January 5th, 2021
Last Modified:
February 13th, 2025
Added to House:
July 21st, 2026
CVSS Vectors
V3:
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N