CVE-2021-28506 | An issue has recently been discovered in Arista EOS where certain gNOI APIs incorrectly skip authorization and authentication which could potentially allow a factory reset of the device.

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An issue has recently been discovered in Arista EOS where certain gNOI APIs incorrectly skip authorization and authentication which could potentially allow a factory reset of the device.

Published: 2022-01-14 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-28506 is rated High Exploit Risk (76.6/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 1.42%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2021-28506

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2021-28506

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.48% 1.42% +0.94%
2 2025-12-22 0.28% 0.48% +0.20%
3 2025-07-15 — 0.28% —

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-28506

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.1 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.2 [email protected]
9.1 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.2 [email protected]
9.4 2.0 HIGH
AV:N/AC:L/Au:N/C:N/I:C/A:C Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
 10.0 9.2 [email protected]

Weakness enumeration for CVE-2021-28506

Affected software / configurations for CVE-2021-28506

Vendor Product Version Raw CPE
arista eos >= 4.24.0, <= 4.24.7m cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:*
arista eos >= 4.25.0, <= 4.25.3 cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:*
arista eos >= 4.25.4, <= 4.25.4m cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:*
arista eos >= 4.25.5, <= 4.25.5.1m cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:*
arista eos >= 4.26.0, <= 4.26.2f cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:*

References for CVE-2021-28506

cvelogic Threat Intelligence