CVE-2021-28499

Complete system access via cleartext stored passwords

Published Sep 9, 2021 · Updated Aug 3, 2024

Credential exposure in Arista Networks MOS affected releases on 7130 systems allows local users to read cleartext account passwords. When a local account is created with the 0 or plaintext option, MOS stores the supplied password unencrypted in the running configuration and copies it into derived outputs such as show tech-support. Low-privilege local access is required; disclosure of one of these stored passwords grants complete access to the affected system.

CVSS severity6.3
Medium
EPSS probability0.21%
Next 30 days · Sep 17, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Credential exposure in Arista Networks MOS affected releases on 7130 systems allows local users to read cleartext account passwords. When a local account is created with the 0 or plaintext option, MOS stores the supplied password unencrypted in the running configuration and copies it into derived outputs such as show tech-support. Low-privilege local access is required; disclosure of one of these stored passwords grants complete access to the affected system.

The record

CVE
CVE-2021-28499
Published
Sep 9, 2021
Updated
Aug 3, 2024
Vendor
Arista Networks
Product
MOS (Metamako Operating System)
Classifications
CWE-255, CWE-522, T1552.001
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 9, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=MOS-0.18 <MOS-0.18*
  2. Affected versionversion=MOS-0.32.0 <MOS-0.32.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Arista Networks · MOS (Metamako Operating System)version=MOS-0.18 <MOS-0.18*; version=MOS-0.32.0 <MOS-0.32.0

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
6.3Arista Networks, Inc.CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L
2.1NIST NVDAV:L/AC:L/Au:N/C:P/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-255Credentials Management Errors
CWE-522Insufficiently Protected Credentials
T1552.001Credentials In Files

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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