CVE-2021-21290: Debian Linux

Medium severity, CVSS 5.5. EPSS: 1.8% chance of exploitation in the next 30 days.

Netty is an open-source, asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients. In Netty before version 4.1.59.Final there is a vulnerability on Unix-like systems involving an insecure temp file. When netty's multipart decoders are used local information disclosure can occur via the local system temporary directory if temporary storing uploads on the disk is enabled. On unix-like systems, the temporary directory is shared between all user. As such, writing to this directory using APIs that do not explicitly set the file/directory permissions can lead to information disclosure. Of note, this does not impact modern MacOS Operating Systems. The method "File.createTempFile" on unix-like systems creates a random file, but, by default will create this file with the permissions "-rw-r--r--". Thus, if sensitive information is written to this file, other local users can read this information. This is the case in netty's "AbstractDiskHttpData" is vulnerable. This has been fixed in version 4.1.59.Final. As a workaround, one may specify your own "java.io.tmpdir" when you start the JVM or use "DefaultHttpDataFactory.setBaseDir(...)" to set the directory to something that is only readable by the current user.

Affected products

  • Debian Debian Linux: version 9.0 only; version 10.0 only
  • Netapp Active Iq Unified Manager: affected versions not specified
  • Netapp Cloud Secure Agent: affected versions not specified
  • Netapp Snapcenter: affected versions not specified
  • Netty Netty: before 4.1.59 (fixed in 4.1.59)
  • Oracle Banking Corporate Lending Process Management: version 14.2.0 only; version 14.3.0 only; version 14.5.0 only
  • Oracle Banking Credit Facilities Process Management: version 14.2.0 only; version 14.3.0 only; version 14.5.0 only
  • Oracle Banking Trade Finance Process Management: version 14.2.0 only; version 14.3.0 only; version 14.5.0 only
  • Oracle Communications Brm - Elastic Charging Engine: version 12.0.0.3 only
  • Oracle Communications Design Studio: version 7.4.2 only
  • Oracle Communications Messaging Server: version 8.1 only
  • Oracle Nosql Database: before 20.3 (fixed in 20.3)
  • Quarkus Quarkus: up to and including 1.13.7

Published 2021-02-08. Last modified 2026-10-08.