This High severity DoS (Denial of Service) vulnerability was introduced in version 9.2.0, 10.3.0 ad 11.0.0 of Jira Software Data Center.

This DoS (Denial of Service) vulnerability, with a CVSS Score of 8.7 and a CVSS Vector of CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N allows an unauthenticated attacker to expose assets in your environment susceptible to exploitation which has no impact to confidentiality, no impact to integrity, high impact to availability, and requires no user interaction.

Atlassian recommends that Jira Software Data Center customers upgrade to latest version, if you are unable to do so, upgrade your instance to one of the specified supported fixed versions:

• Jira Software Data Center 11.0: Upgrade to a release greater than or equal to 11.1.0
• Jira Software Data Center 10.3: Upgrade to a release greater than or equal to 10.3.11
• Jira Software Data Center 9.12: Upgrade to a release greater than or equal to 9.12.28

See the release notes (https://www.atlassian.com/software/jira/download-archives). You can download the latest version of Jira Software Data Center from the download center (https://www.atlassian.com/software/jira/download-archives).

The National Vulnerability Database provides the following description for this vulnerability:

Netty is an asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients. In netty-codec-compression versions 4.1.124.Final and below, and netty-codec versions 4.2.4.Final and below, when supplied with specially crafted input, BrotliDecoder and certain other decompression decoders will allocate a large number of reachable byte buffers, which can lead to denial of service. BrotliDecoder.decompress has no limit in how often it calls pull, decompressing data 64K bytes at a time. The buffers are saved in the output list, and remain reachable until OOM is hit. This is fixed in versions 4.1.125.Final of netty-codec and 4.2.5.Final of netty-codec-compression.