CVE-2021-0203
No exploitation reported by the sources we read.
- Published2021-01-15
- WeaknessCWE-794
Am I affected?
Debian, Ubuntu or Red Hat sometimes backport a fix without changing the upstream version number: such a version reads « to verify », never « affected ».With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.
Description
On Juniper Networks EX and QFX5K Series platforms configured with Redundant Trunk Group (RTG), Storm Control profile applied on the RTG interface might not take affect when it reaches the threshold condition. Storm Control enables the device to monitor traffic levels and to drop broadcast, multicast, and unknown unicast packets when a specified traffic level is exceeded, thus preventing packets from proliferating and degrading the LAN. Note: this issue does not affect EX2200, EX3300, EX4200, and EX9200 Series. This issue affects Juniper Networks Junos OS on EX Series and QFX5K Series: 15.1 versions prior to 15.1R7-S7; 16.1 versions prior to 16.1R7-S8; 17.2 versions prior to 17.2R3-S4; 17.3 versions prior to 17.3R3-S8; 17.4 versions prior to 17.4R2-S11, 17.4R3-S2; 18.1 versions prior to 18.1R3-S10; 18.2 versions prior to 18.2R3-S5; 18.3 versions prior to 18.3R2-S4, 18.3R3-S2; 18.4 versions prior to 18.4R2-S5, 18.4R3-S3; 19.1 versions prior to 19.1R2-S2, 19.1R3-S2; 19.2 versions prior to 19.2R1-S5, 19.2R2-S1, 19.2R3; 19.3 versions prior to 19.3R2-S4, 19.3R3; 19.4 versions prior to 19.4R1-S3, 19.4R2-S1, 19.4R3; 20.1 versions prior to 20.1R1-S2, 20.1R2.
Timeline
dates in UTC- 2021-01-1518:15CVE publishedNVD
Observed activity
isMalicious corpus · updated 2026-10-23 21:37 UTCBlock these indicators
- Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-0203?format=txt
- CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-0203?format=csv
- TAXII collection of exploited CVEs
- The EDL and CSV take an API key on the Pro plan.
Versions per branch
NVD| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 15.1 | = 15.1 | no fix published | NVD |
| 16.1 | = 16.1 | no fix published | NVD |
| 17.2 | = 17.2 | no fix published | NVD |
| 17.4 | = 17.4 | no fix published | NVD |
| 18.1 | = 18.1 | no fix published | NVD |
| 18.2 | = 18.2 | no fix published | NVD |
| 18.3 | = 18.3 | no fix published | NVD |
| 18.4 | = 18.4 | no fix published | NVD |
| 19.1 | = 19.1 | no fix published | NVD |
| 19.2 | = 19.2 | no fix published | NVD |
| 19.3 | = 19.3 | no fix published | NVD |
| 19.4 | = 19.4 | no fix published | NVD |
as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.
Fix
Advisories and patches
- kb.juniper.netVendor Advisory
Detection
- Nuclei template
- none so far ProjectDiscovery
- Exploit-DB
- no entry Exploit-DB
- Proof-of-concept repositories
- none listed PoC-in-GitHub
Sources
- CNACVSS 3.18.6read 2026-10-23
- NVDCVSS 2.04.3read 2026-10-23
- CNAweakness (CWE)CWE-794read 2026-10-23
- FIRST EPSSEPSS score1.0 %2026-10-23
Technical details
- CVSS v3 Vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
- Published
- 2021-01-15
- Last Modified
- 2026-06-17
- NVD status
- Modified
Frequently asked questions
What is CVE-2021-0203?
Is CVE-2021-0203 actively exploited?
What is the CVSS score for CVE-2021-0203?
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