What’s Vulnerable › Vulnerabilities
CVE-2021-3121: Panic due to improper input validation in github.com/gogo/protobuf
- Severity: high (CVSS 8.6 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 3.4% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2021-01-11 · updated 2026-06-17
- Weakness: CWE-129
Description
An issue was discovered in GoGo Protobuf before 1.3.2. plugin/unmarshal/unmarshal.go lacks certain index validation, aka the "skippy peanut butter" issue.
Affected products
- Golang Protobuf: before 1.3.2 — fixed in 1.3.2
- HashiCorp Consul: before 1.8.15; from 1.9.0 before 1.9.9; from 1.10.0 before 1.10.2 — fixed in 1.10.2, 1.8.15, 1.9.9
- Go Github.Com/Gogo/Protobuf: before 1.3.2 — fixed in 1.3.2
How to fix
Upgrade to a fixed version: Golang Protobuf 1.3.2; HashiCorp Consul 1.10.2, 1.8.15, 1.9.9; Go Github.Com/Gogo/Protobuf 1.3.2. Check the vendor advisory for mitigations.
References
- https://discuss.hashicorp.com/t/hcsec-2021-23-consul-exposed-to-denial-of-service-in-gogo-protobuf-dependency/29025
- https://github.com/gogo/protobuf/commit/b03c65ea87cdc3521ede29f62fe3ce239267c1bc
- https://github.com/gogo/protobuf/compare/v1.3.1...v1.3.2
- https://lists.apache.org/thread.html/r68032132c0399c29d6cdc7bd44918535da54060a10a12b1591328bff%40%3Cnotifications.skywalking.apache.org%3E
- https://lists.apache.org/thread.html/r88d69555cb74a129a7bf84838073b61259b4a3830190e05a3b87994e%40%3Ccommits.pulsar.apache.org%3E
- https://lists.apache.org/thread.html/rc1e9ff22c5641d73701ba56362fb867d40ed287cca000b131dcf4a44%40%3Ccommits.pulsar.apache.org%3E
- https://security.netapp.com/advisory/ntap-20210219-0006/
- https://discuss.hashicorp.com/t/hcsec-2021-23-consul-exposed-to-denial-of-service-in-gogo-protobuf-dependency/29025
- https://github.com/gogo/protobuf/commit/b03c65ea87cdc3521ede29f62fe3ce239267c1bc
- https://github.com/gogo/protobuf/compare/v1.3.1...v1.3.2
- https://lists.apache.org/thread.html/r68032132c0399c29d6cdc7bd44918535da54060a10a12b1591328bff%40%3Cnotifications.skywalking.apache.org%3E
- https://lists.apache.org/thread.html/r88d69555cb74a129a7bf84838073b61259b4a3830190e05a3b87994e%40%3Ccommits.pulsar.apache.org%3E
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