CVE-2021-3121: golang protobuf Improper Validation of Array Index
Modified
AliasesALPINE-CVE-2021-3121SUSE-SU-2025:02977-1UBUNTU-CVE-2021-3121DEBIAN-CVE-2021-3121CGA-25rr-5xj5-74xjCGA-2fw2-89g7-36mrCGA-324p-44gq-32g5CGA-34fm-8f64-5vfqCGA-3q23-vchw-gv52CGA-4p47-37hr-mq9fCGA-4vvq-6phf-h444CGA-5pwv-m5v2-qc6hCGA-6g3w-g682-jvr5CGA-7jwv-7p5g-g6qvCGA-7vwx-86cg-gp5fCGA-94j5-qw9w-c8x4CGA-9qcq-69r9-c79mCGA-ccqc-357v-mgq8CGA-cv25-7f58-fxqwCGA-fmf5-g6jg-6rjfCGA-g8fh-pwfp-54qhCGA-hp3r-9452-5g8cCGA-hxqc-77xp-wc8gCGA-j62m-xmw8-fw2hCGA-jp54-mp54-j5vhCGA-jwgm-2qrh-rvghCGA-mjf6-8hm4-pr6fCGA-mp3q-59cp-fjfhCGA-p36q-rww5-7w3vCGA-p65g-xpx7-r77cCGA-pxwm-f8xx-97v7CGA-q2vp-wr62-fwmrCGA-q35g-rcp8-c255CGA-q46x-854v-v5pvCGA-q93h-mvv8-82c3CGA-qhh4-6pxc-q9fmCGA-qj7w-6c79-qq37CGA-rfx8-52j2-5gpxCGA-wf45-7vcp-486vCGA-x473-676j-2246GHSA-c3h9-896r-86jmBIT-consul-2021-3121BIT-protobuf-2021-3121GO-2021-0053openSUSE-SU-2024:10902-1openSUSE-SU-2024:10903-1openSUSE-SU-2024:10904-1openSUSE-SU-2024:10905-1openSUSE-SU-2024:11553-1openSUSE-SU-2024:11554-1CGA-35q3-294g-cc3rCGA-383c-7q7q-6f3gCGA-3vpm-wcm3-39jrCGA-44qq-cw32-q87mCGA-45w8-w2vr-hjgfCGA-4hr9-gqjv-rvx4CGA-5hrv-wpmx-2g5cCGA-5j28-cq9r-8cjrCGA-5pfv-c4wq-8m7gCGA-6qc3-c2cc-grrfCGA-7287-ww5g-83pxCGA-7f5j-wmmj-4f3vCGA-842r-r4c2-hjqhCGA-9528-gxm4-fx6qCGA-9vg7-83wh-569gCGA-cvpj-7rr3-qmwxCGA-f7vp-x3gj-5xcfCGA-gff4-5jm5-jg47CGA-gq74-48r4-h8g9CGA-m285-4vf4-38r8CGA-p2p5-v8cg-6f9gCGA-q4x2-vj2r-8p4jCGA-r45q-84pr-55j5CGA-rj7f-6vh5-279rCGA-v9g9-96cp-v4rwCGA-wq24-prx5-8whr
Published 11-01-2021Last modified 03-08-2024
Vulnerability summary
CVE-2021-3121 is a high (CVSS 8.6) Improper Validation of Array Index vulnerability in golang protobuf. EPSS estimates a 3.43% chance of exploitation in the next 30 days, higher than 88.9% of scored vulnerabilities.
Priority
Prioritisesevere
Severe, CVSS 8.6 (NVD); no exploitation reported by the 5 checked sources; EPSS 3% (FIRST, 03-11-2026)
Source freshness unavailable
How is this decided?CVSS score
8.6/10
010
High · v3.1 (NVD)EPSS score
3.43%
0%100%
Low · +0.04 pp in 30 daysKEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 4 · Related 5Timeline
- 11-01-2021PublishedVulnerability first disclosed.
- 03-08-2024Last modifiedVulnerability information updated.
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.
CVSS metrics
8 scores · 7 sources · 2 versionsHigh 8.6Preferred score · NVD (NIST)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:HSourcesAll 7 agree
- OSV · AlpineEcosystem advisory · calculated8.6HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H
- OSV · UbuntuEcosystem advisory · calculated8.6HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H
- OSV · DebianEcosystem advisory · calculated8.6HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H
- OSV · WolfiEcosystem advisory · calculated8.6HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H
- OSV · GoEcosystem advisory · calculated8.6HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H
- OSV · ChainguardEcosystem advisory · calculated8.6HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H
High 7.5Preferred score · NVD (NIST)
AV:N/AC:L/Au:N/C:P/I:P/A:PSourcesSingle source
EPSS trend
Probability
3.43%
Chance of exploitation in the next 30 days
Percentile
89%
Versus all other CVEs
30-day change
Increase +0.04 pp
From 3.38% on 04-10-2026
04-10-202603-11-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Version check
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Chainguard31 products
- ctop< 0.7.7-r13
- k3d< 5.6.0-r11
- k3d-proxy< 5.6.0-r11
- k3d-tools< 5.6.0-r11
- kubeflow< 1.10.0-r3
Wolfi18 products
- ctop< 0.7.7-r13
- k3d< 5.6.0-r11
- k3d-proxy< 5.6.0-r11
- k3d-tools< 5.6.0-r11
- kubeflow< 1.10.0-r3
Suse8 products
- kubernetes1.18&distro=SUSE Enterprise Storage 7.1< 1.18.20-150200.5.25.1
- kubernetes1.18&distro=SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS< 1.18.20-150200.5.25.1
- kubernetes1.18&distro=SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS< 1.18.20-150200.5.25.1
- kubernetes1.18&distro=SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS< 1.18.20-150200.5.25.1
- kubernetes1.18&distro=SUSE Linux Enterprise Server 15 SP3-LTSS< 1.18.20-150200.5.25.1
Opensuse7 products
- kubernetes1.18&distro=openSUSE Leap 15.6< 1.18.20-150200.5.25.1
- kubernetes1.18&distro=openSUSE Tumbleweed< 1.18.20-1.2
- kubernetes1.19&distro=openSUSE Tumbleweed< 1.19.15-1.1
- kubernetes1.20&distro=openSUSE Tumbleweed< 1.20.11-1.1
- kubernetes1.21&distro=openSUSE Tumbleweed< 1.21.5-1.1
Alpine1 product
- protobuf-c< 1.3.2-r0
Debian1 product
- golang-gogoprotobuf< 1.3.2-1
Github.com/gogo1 product
- protobuf< 1.3.2
Golang1 product
- protobuf< 1.3.2
Hashicorp1 product
- consul< 1.8.15 | ≥ 1.9.0, < 1.9.9 | ≥ 1.10.0, < 1.10.2
Ubuntu1 product
- golang-gogoprotobufAll versions (No fix recorded) | < 1.3.2-1
10 vendors · 70 products
References
22 links- github.com/gogo/protobuf/commit/b03c65ea87cdc3521ede29f62fe3ce239267c1bcX Refsource MISCFIXWEBPatchThird Party Advisory
- github.com/gogo/protobuf/compare/v1.3.1...v1.3.2X Refsource MISCREPORTFIXWEBPatchThird Party Advisory
Show all 22 references
- github.com/gogo/protobufPACKAGE