This High severity org.xerial.snappy:snappy-java Dependency vulnerability was introduced in versions 7.21.0, 8.9.0 and 8.13.0 of Bitbucket Data Center and Server.

This org.xerial.snappy:snappy-java Dependency vulnerability, with a CVSS Score of 7.5 and a CVSS Vector of CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H 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 Bitbucket Data Center and Server customers upgrade to latest version, if you are unable to do so, upgrade your instance to one of the specified supported fixed versions:

• Bitbucket Data Center and Server 7.21: Upgrade to a release greater than or equal to 7.21.21

• Bitbucket Data Center and Server 8.9: Upgrade to a release greater than or equal to 8.9.5

• Bitbucket Data Center and Server 8.13: Upgrade to a release greater than or equal to 8.13.1

See the release notes (https://confluence.atlassian.com/bitbucketserver/release-notes). You can download the latest version of Bitbucket Data Center and Server from the download center (https://www.atlassian.com/software/bitbucket/download-archives).

The National Vulnerability Database provides the following description for this vulnerability: snappy-java is a fast compressor/decompressor for Java. Due to use of an unchecked chunk length, an unrecoverable fatal error can occur in versions prior to 1.1.10.1.

The code in the function hasNextChunk in the fileSnappyInputStream.java checks if a given stream has more chunks to read. It does that by attempting to read 4 bytes. If it wasn’t possible to read the 4 bytes, the function returns false. Otherwise, if 4 bytes were available, the code treats them as the length of the next chunk.

In the case that the `compressed` variable is null, a byte array is allocated with the size given by the input data. Since the code doesn’t test the legality of the `chunkSize` variable, it is possible to pass a negative number (such as 0xFFFFFFFF which is -1), which will cause the code to raise a `java.lang.NegativeArraySizeException` exception. A worse case would happen when passing a huge positive value (such as 0x7FFFFFFF), which would raise the fatal `java.lang.OutOfMemoryError` error.

Version 1.1.10.1 contains a patch for this issue.