Summary
A potential Denial of Service issue in protobuf-java
A potential Denial of Service issue in protobuf-java was discovered in the parsing procedure for binary data.
Reporter: 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 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)
Impact
CVE-2021-22569 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (3.16.1, 3.19.2, 3.18.2); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Already deployed Kodem?
See it in your environmentNew to Kodem? Get a demo →Remediation advice
com.google.protobuf:protobuf-java to 3.16.1 or later; google-protobuf to 3.19.2 or later; com.google.protobuf:protobuf-java to 3.18.2 or later; com.google.protobuf:protobuf-java to 3.19.2 or later; com.google.protobuf:protobuf-kotlin to 3.18.2 or later; com.google.protobuf:protobuf-kotlin to 3.19.2 or later
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2021-22569? CVE-2021-22569 is a high-severity security vulnerability in com.google.protobuf:protobuf-java (maven), affecting versions < 3.16.1. It is fixed in 3.16.1, 3.19.2, 3.18.2.
- How severe is CVE-2021-22569? CVE-2021-22569 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which packages are affected by CVE-2021-22569?
com.google.protobuf:protobuf-java(maven) (versions < 3.16.1)google-protobuf(rubygems) (versions < 3.19.2)com.google.protobuf:protobuf-kotlin(maven) (versions >= 3.18.0, < 3.18.2)
- Is there a fix for CVE-2021-22569? Yes. CVE-2021-22569 is fixed in 3.16.1, 3.19.2, 3.18.2. Upgrade to this version or later.
- Is CVE-2021-22569 exploitable, and should I be worried? Whether CVE-2021-22569 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2021-22569 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2021-22569?
- Upgrade
com.google.protobuf:protobuf-javato 3.16.1 or later - Upgrade
google-protobufto 3.19.2 or later - Upgrade
com.google.protobuf:protobuf-javato 3.18.2 or later - Upgrade
com.google.protobuf:protobuf-javato 3.19.2 or later - Upgrade
com.google.protobuf:protobuf-kotlinto 3.18.2 or later - Upgrade
com.google.protobuf:protobuf-kotlinto 3.19.2 or later
- Upgrade