CVE-2021-34757

Privilege escalation via firmware-wide static password

Published Oct 6, 2021 · Updated Nov 7, 2024

A static password in Cisco 220 Series Smart Plus Switches firmware 1.2.0.6 and earlier allows physically proximate attackers to escalate privileges. Every affected firmware image uses the same password, which exposes encoded account passwords through the serial interface. Physical access and Administrator privileges are required; exploitation reveals account passwords and permits their reconfiguration.

CVSS severity5.5
Medium
EPSS probability0.62%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A static password in Cisco 220 Series Smart Plus Switches firmware 1.2.0.6 and earlier allows physically proximate attackers to escalate privileges. Every affected firmware image uses the same password, which exposes encoded account passwords through the serial interface. Physical access and Administrator privileges are required; exploitation reveals account passwords and permits their reconfiguration.

The record

CVE
CVE-2021-34757
Published
Oct 6, 2021
Updated
Nov 7, 2024
Vendor
ClamAV
Product
Cisco 220 Series Smart Plus Switches
Classifications
CWE-540, T1555, T1098
Attack vector
physical
Privileges
admin

Timeline

How it unfolded

  1. Oct 6, 2021CVE publishedPublication date reported by the CVE source.
  2. Nov 7, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=n/a

What conditions does exploitation require?

Attack vectorphysical
Required privilegesadmin

What is affected?

ClamAV · Cisco 220 Series Smart Plus Switchesversion=n/a

Published CVSS scores

5.5CiscoCVSS:3.1/AV:P/AC:L/PR:H/UI:N/S:U/C:H/I:H/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.

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No observations available

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

Weakness, pattern, technique

CWE-540Inclusion of Sensitive Information in Source Code
T1555Credentials from Password Stores
T1098Account Manipulation

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

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Your stack

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