CVE-2021-28507 | 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.

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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.

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-2021-28507 is rated Exploit Available (54/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.67%). 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-2021-28507

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

Exploit prediction scoring system (EPSS) score for CVE-2021-28507

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 0.06% 0.67% +0.61%
2 2023-03-07 0.89% 0.06% -0.83%
3 2022-02-04 — 0.89% —

Full EPSS history (4 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-28507

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:H/A:N 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:H)
They need powerful rights—admin, root, or similar—before this pays off.
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:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 1.2 4.2 [email protected]
7.1 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N 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:L)
A normal user session is enough; they don’t have to be admin.
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:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 4.2 [email protected]
4.9 2.0 MEDIUM
AV:N/AC:M/Au:S/C:P/I:P/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:S)
A single authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
 6.8 4.9 [email protected]

Weakness enumeration for CVE-2021-28507

Affected software / configurations for CVE-2021-28507

Vendor Product Version Raw CPE
arista eos >= 4.23.0, <= 4.23.9m cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:*
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:*:*:*:*:*:*:*:*
arista eos 4.21.0f cpe:2.3:o:arista:eos:4.21.0f:*:*:*:*:*:*:*
arista eos 4.21.1f cpe:2.3:o:arista:eos:4.21.1f:*:*:*:*:*:*:*
arista eos 4.21.3f cpe:2.3:o:arista:eos:4.21.3f:*:*:*:*:*:*:*
arista eos 4.22.0f cpe:2.3:o:arista:eos:4.22.0f:*:*:*:*:*:*:*
arista eos 4.22.1f cpe:2.3:o:arista:eos:4.22.1f:*:*:*:*:*:*:*

References for CVE-2021-28507

cvelogic Threat Intelligence