Cyber Resilience

CVE-2021-28506

CriticalPublic PoC

Published: 14 January 2022

Published
14 January 2022
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
EPSS Score 0.0048 65.6th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-28506 is a critical-severity Improper Authorization (CWE-285) vulnerability in Arista Eos. Its CVSS base score is 9.1 (Critical).

Operationally, ranked in the top 34.4% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

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.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

arista
eos
4.24.0 — 4.24.7m · 4.25.0 — 4.25.3 · 4.25.4 — 4.25.4m

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

Requiring identification and rationale for actions allowed without authentication ensures critical functions are not left unprotected by forcing review of authentication requirements.

Mandating explicit authorization of mobile device connections reduces the risk of improper authorization decisions for system access.

Ensures authorization decisions are always performed by a complete and analyzable reference monitor.

Auditing session actions allows identification of improper authorization decisions and enforcement failures.

The process verifies authorization mechanisms function as intended before system approval.

Dedicated authorization servers support policy-based decisions, mitigating improper authorization.

Procedures define authorization decisions tied to hiring, transfer, and termination, reducing the likelihood of improper authorization decisions.

Criticality analysis identifies functions whose authorization decisions must be correct, making improper authorization flaws less likely to remain exploitable in those areas.

References