Affected: Maven: com.google.protobuf:protobuf-java, RubyGems: google-protobuf, Maven: com.google.protobuf:protobuf-kotlin

## Summary

A potential Denial of Service issue in protobuf-java was discovered in the parsing procedure for binary data.

Reporter: [OSS-Fuzz](https://github.com/google/oss-fuzz)

Affected versions: All versions of Java Protobufs (including Kotlin and JRuby) prior to the versions listed below. Protobuf "javalite" users (typically Android) are not affected.

## Severity

[CVE-2021-22569](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-22569) **High** - CVSS Score: 7.5, An implementation weakness in how unknown fields are parsed in Java. A small (~800 KB) malicious payload can occupy the parser for several minutes by creating large numbers of short-lived objects that cause frequent, repeated GC pauses.

## Proof of Concept

For reproduction details, please refer to the oss-fuzz issue that identifies the specific inputs that exercise this parsing weakness.

## Remediation and Mitigation

Please update to the latest available versions of the following packages:

- protobuf-java (3.16.1, 3.18.2, 3.19.2) - protobuf-kotlin (3.18.2, 3.19.2) - google-protobuf [JRuby gem only] (3.19.2)