Cyber Resilience

CVE-2021-28505

HighPublic PoC

Published: 14 April 2022

Published
14 April 2022
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS Score 0.0020 42.4th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-28505 is a high-severity Improper Access Control (CWE-284) vulnerability in Arista Eos. Its CVSS base score is 7.5 (High).

Operationally, ranked at the 42.4th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

On affected Arista EOS platforms, if a VXLAN match rule exists in an IPv4 access-list that is applied to the ingress of an L2 or an L3 port/SVI, the VXLAN rule and subsequent ACL rules in that access list will…

more

ignore the specified IP protocol.

CWE(s)

Related Threats

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

Affected Assets

arista
eos
4.26 — 4.26.4m · 4.27 — 4.27.1f

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.

addresses: CWE-284 CWE-863

The access control policy and procedures directly mandate and enforce proper access control mechanisms across the organization.

addresses: CWE-284 CWE-863

Supervision and review of access control activities directly detects and remediates improper access configurations or usages.

addresses: CWE-284 CWE-863

Associating and retaining security attributes with data directly supports enforcement of access control decisions across storage, processing, and transmission.

addresses: CWE-284 CWE-863

Requiring prior authorization for each remote access type prevents improper access control over remote connections.

addresses: CWE-284 CWE-863

Requiring authorization of wireless access before allowing connections enforces proper access control for this access method.

addresses: CWE-284 CWE-863

Requiring authorization and configuration controls for mobile device connections directly enforces access control and prevents unauthorized devices from reaching organizational systems.

addresses: CWE-284 CWE-863

Defining account types, requiring approvals for creation, specifying authorizations, monitoring usage, and reviewing accounts directly prevents improper access control by ensuring only authorized accounts exist and are used.

addresses: CWE-284 CWE-863

Enforces rules governing access to the system and its data from external systems based on established trust relationships.

References