Junos OS: QFX5000 Series and EX4600 Series: Enhanced storm control might not work leading to partial Denial of Service
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · Low
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA.
Summary
A vulnerability in Juniper Networks Junos OS, which only affects the release 18.4R2-S5, where a function is inconsistently implemented on Juniper Networks Junos QFX5000 Series and EX4600 Series, and if "storm-control enhanced" is configured, can lead to the enhanced storm control filter group not be installed. It will cause storm control not to work hence allowing an attacker to cause high CPU usage or packet loss issues by sending a large amount of broadcast or unknown unicast packets arriving the device. This issue affects Juniper Networks QFX5100, QFX5110, QFX5120, QFX5200, QFX5210, EX4600, and EX4650, and QFX5100 with QFX 5e Series image installed. QFX5130 and QFX5220 are not affected from this issue. This issue affects Juniper Networks Junos OS 18.4R2-S5 on QFX5000 Series and EX4600 Series. No other product or platform is affected by this vulnerability.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Juniper | Junos OS | 18.4R2-S5 | — | No fix listed | CNA |
- Junos OS VendorJuniper Affected 18.4R2-S5 Fixed in — No fix listed CNA
CPE configurations NVD · 8
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:juniper:junos:18.4:r2-s5:*:*:*:*:*:* | 18.4 r2-s5 | Vulnerable | Juniper |
| cpe:2.3:h:juniper:ex4600:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:ex4650:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:qfx5100:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:qfx5110:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:qfx5120:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:qfx5200:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:qfx5210:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
- cpe:2.3:o:juniper:junos:18.4:r2-s5:*:*:*:*:*:* Versions 18.4 r2-s5 Vulnerable ·Juniper
- cpe:2.3:h:juniper:ex4600:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:ex4650:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:qfx5100:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:qfx5110:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:qfx5120:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:qfx5200:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:qfx5210:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2021-0294
- 2026-10-03 Alias added: GHSA-2x7j-733f-cc2j
References
Advisory 1
More Juniper Junos vulnerabilities
- TI-2023-18638 Junos OS: EX and SRX Series: A PHP vulnerability in J-Web allows an unauthenticated to… KEVCVSS 3.1CRITICAL 9.8
- TI-2020-01585 Out of Cycle Security Advisory: Junos OS: Security vulnerability in J-Web and web based (HTTP/HTTPS) services KEVCVSS 3.1CRITICAL 9.8
- TI-2015-04610 Assertion failure in ISC BIND named via TKEY queries KEVCVSS 3.1HIGH 7.5
- TI-2025-15550 Junos OS: An local attacker with shell access can execute arbitrary code KEVCVSS 4.0MEDIUM 6.7
- TI-2023-18644 Junos OS: SRX Series: A vulnerability in J-Web allows an unauthenticated attacker to upload and download arbitrary files KEVCVSS 3.1MEDIUM 5.3
- TI-2023-18640 Junos OS: EX Series: A vulnerability in J-Web allows an unauthenticated attacker to upload arbitrary files KEVCVSS 3.1MEDIUM 5.3
Sources
- CVE-2021-0294 · CVE Program
- CVE-2021-0294 · NVD
- FIRST EPSS
- GHSA-2x7j-733f-cc2j · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences