Vulnerability · CVE-2021-3121
HCSEC-2021-23 - Consul Exposed to Denial of Service in GoGo Protobuf Dependency
Published Sep 1, 2021 · HashiCorp
Open the advisory
Exploitation likelihood is not on this record for CVE-2021-3121. A missing EPSS score is not a low risk. Compare HashiCorp with the linked advisory before you change production.
Gaps on this record
- No version range is stored. A customer cannot check an installed version against this record.
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- EPSS is missing. A missing score is not a low risk.
- Severity
- Unknown—
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- Not in the current FIRST EPSS dataset
- Remediation
- Not established
- Affected products
- HashiCorp
...onsul”) were vulnerable to denial of service due to a flaw in the gogo/protobuf module used for Consul’s protocol buffer support. This vulnerability, CVE-2021-3121, was addressed in Consul and Consul Enterprise 1.8.15, 1.9.9 and 1.10.2. Background Consul has a dependency on the https://github.com/gogo/...
No affected version ranges are stored yet. Use the vendor advisory before you decide this record does not apply.
How to fix CVE-2021-3121
Recommended remediation
No required-action text, fix commit, or clear fixed-version range is stored yet.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
Exploitation likelihood is not on this record for CVE-2021-3121. A missing EPSS score is not a low risk. Compare HashiCorp with the linked advisory before you change production.
Which versions are affected?
Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
No weakness class is stored. EPSS is absent from the current FIRST dataset. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Sep 1, 2021 · HashiCorp Security
Detected
...onsul”) were vulnerable to denial of service due to a flaw in the gogo/protobuf module used for Consul’s protocol buffer support. This vulnerability, CVE-2021-3121, was addressed in Consul and Consul Enterprise 1.8.15, 1.9.9 and 1.10.2. Background Consul has a dependency on the https://github.com/gogo/...
Sources
- CVE.orgVulnerability recordCVE-2021-3121
Official CVE identifier
cve.org - HashiCorp SecurityVendor advisoryCVE-2021-3121
...onsul”) were vulnerable to denial of service due to a flaw in the gogo/protobuf module used for Consul’s protocol buffer support. This vulnerability, CVE-2021-3121, was addressed in Consul and Consul Enterprise 1.8.15, 1.9.9 and 1.10.2. Background Consul has a dependency on th
discuss.hashicorp.com
Freshness
Last verified in this catalog Oct 23, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.