CVE-2020-3147Network attack vector

Unauthenticated reload via malformed web request

Published Jan 29, 2020 · Updated Nov 15, 2024

Improper input validation in Cisco Small Business 300 Series Managed Switches before 1.3.7.18 allows remote attackers to cause DoS via web requests. The web interface accepts a maliciously formed request without proper validation and can unexpectedly reload the switch. No authentication is required, but the request must reach the device's web interface; successful exploitation interrupts service through an unexpected reload.

CVSS severity8.6
High
EPSS probability2.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in Cisco Small Business 300 Series Managed Switches before 1.3.7.18 allows remote attackers to cause DoS via web requests. The web interface accepts a maliciously formed request without proper validation and can unexpectedly reload the switch. No authentication is required, but the request must reach the device's web interface; successful exploitation interrupts service through an unexpected reload.

The record

CVE
CVE-2020-3147
Published
Jan 29, 2020
Updated
Nov 15, 2024
Vendor
ClamAV
Product
Cisco Small Business 300 Series Managed Switches
Classifications
CWE-20, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 29, 2020CVE publishedPublication date reported by the CVE source.
  2. Nov 15, 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=unspecified <1.3.7.18

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ClamAV · Cisco Small Business 300 Series Managed Switchesversion=unspecified <1.3.7.18

Published CVSS scores

8.6CiscoCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
T1499Endpoint Denial of Service

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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