HOMEVULNERABILITIESCVE-2021-28503
CRITICAL

CVE-2021-28503

CWE-305Published: February 4, 2022· Updated: Jun 17, 2026

9.8
CVSS v3.1

Official Description

The impact of this vulnerability is that Arista's EOS eAPI may skip re-evaluating user credentials when certificate based authentication is used, which allows remote attackers to access the device via eAPI.

NVD Source

Technical Analysis

CVE-2021-28503 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Vendors & Products

arista1 product(s)
eos
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://www.arista.com/en/support/advisories-notices/security-advisories/13605-security-advisory-0072
PATCHhttps://www.arista.com/en/support/advisories-notices/security-advisories/13605-security-advisory-0072

All References (2)

→
https://www.arista.com/en/support/advisories-notices/security-advisories/13605-security-advisory-0072Mitigation · Patch · Vendor Advisory
→
https://www.arista.com/en/support/advisories-notices/security-advisories/13605-security-advisory-0072Mitigation · Patch · Vendor Advisory

Quick Facts

CVE IDCVE-2021-28503
CVSS Score9.8 / 10
SeverityCRITICAL
WeaknessCWE-305
CISA KEVNo
Affected1 vendor(s)
PublishedFeb 4, 2022

Related CVEs (CWE-305)

CVE-2025-24522
10.0
CVE-2024-50478
9.8
CVE-2024-36388
9.8
CVE-2023-34137
9.8
CVE-2024-1202
9.8
CVE-2022-2651
9.8

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-28503 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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