Improper access control in Arista EOS
Priority LOW 32CWE-284Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- Low · High · None
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-284.
Summary
An issue has recently been discovered in Arista EOS where, under certain conditions, the service ACL configured for OpenConfig gNOI and OpenConfig RESTCONF might be bypassed, which results in the denied requests being forwarded to the agent.
Why it matters now
EPSS 0.00691 53rd percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix No fix listed No fixed version in the sources yet
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 |
|---|---|---|---|---|---|
| Arista | EOS | 4.22.x; 4.26.2F – 4.26.0; 4.25.5.1M – 4.25.5; 4.25.4M – 4.25.4; 4.25.3 – 4.25.0; 4.24.7M – 4.24.0; 4.23.9M – 4.23.0; 4.21.x – 4.21.x | — | No fix listed | CNA |
- EOS VendorArista Affected 4.22.x; 4.26.2F – 4.26.0; 4.25.5.1M – 4.25.5; 4.25.4M – 4.25.4; 4.25.3 – 4.25.0; 4.24.7M – 4.24.0; 4.23.9M – 4.23.0; 4.21.x – 4.21.x Fixed in — No fix listed CNA
CPE configurations NVD · 6
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:* | 4.23.0 – 4.23.9m; 4.24.0 – 4.24.7m; 4.25.0 – 4.25.3; 4.25.4 – 4.25.4m; 4.25.5 – 4.25.5.1m; 4.26.0 – 4.26.2f | Vulnerable | Arista |
| cpe:2.3:o:arista:eos:4.21.0f:*:*:*:*:*:*:* | 4.21.0f | Vulnerable | Arista |
| cpe:2.3:o:arista:eos:4.21.1f:*:*:*:*:*:*:* | 4.21.1f | Vulnerable | Arista |
| cpe:2.3:o:arista:eos:4.21.3f:*:*:*:*:*:*:* | 4.21.3f | Vulnerable | Arista |
| cpe:2.3:o:arista:eos:4.22.0f:*:*:*:*:*:*:* | 4.22.0f | Vulnerable | Arista |
| cpe:2.3:o:arista:eos:4.22.1f:*:*:*:*:*:*:* | 4.22.1f | Vulnerable | Arista |
- cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:* Versions 4.23.0 – 4.23.9m; 4.24.0 – 4.24.7m; 4.25.0 – 4.25.3; 4.25.4 – 4.25.4m; 4.25.5 – 4.25.5.1m; 4.26.0 – 4.26.2f Vulnerable ·Arista
- cpe:2.3:o:arista:eos:4.21.0f:*:*:*:*:*:*:* Versions 4.21.0f Vulnerable ·Arista
- cpe:2.3:o:arista:eos:4.21.1f:*:*:*:*:*:*:* Versions 4.21.1f Vulnerable ·Arista
- cpe:2.3:o:arista:eos:4.21.3f:*:*:*:*:*:*:* Versions 4.21.3f Vulnerable ·Arista
- cpe:2.3:o:arista:eos:4.22.0f:*:*:*:*:*:*:* Versions 4.22.0f Vulnerable ·Arista
- cpe:2.3:o:arista:eos:4.22.1f:*:*:*:*:*:*:* Versions 4.22.1f Vulnerable ·Arista
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2021-28507
- 2026-10-03 Alias added: GHSA-4j73-jx76-fgw8
References
More Arista Eos vulnerabilities
- TI-2014-05975 GNU Bash through 4.3 bash43-025 processes trailing strings after certain malformed… KEVCVSS 3.1CRITICAL 9.8
- TI-2014-05157 GNU Bash through 4.3 processes trailing strings after function definitions in the values… KEVCVSS 3.1CRITICAL 9.8
- TI-2026-06569 Arista EOS Unexpected Tunnel Protocol Decapsulation and Forwarding Bypass KEVCVSS 4.0MEDIUM 6.9
- TI-2017-10594 Heap-based buffer overflow in dnsmasq before 2.78 allows remote attackers to cause a… CVSS 3.1CRITICAL 9.8
- TI-2024-05929 Openssh: regresshion - race condition in ssh allows rce/dos CVSS 3.1HIGH 8.1
- TI-2020-08209 utility.c in telnetd in netkit telnet through 0.17 allows remote attackers to execute… CVSS 3.1CRITICAL 9.8
Sources
- CVE-2021-28507 · CVE Program
- CVE-2021-28507 · NVD
- FIRST EPSS
- GHSA-4j73-jx76-fgw8 · GitHub Advisory Database · CC BY 4.0
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