CVE-2020-8157Public exploit

Root access via unprotected UART interface

Published May 2, 2020 · Updated Aug 4, 2024

Improper access control in Ubiquiti UniFi Cloud Key firmware 1.1.10 and earlier allows local users to gain root access via UART. The serial console exposes a root shell without authentication, even when application and management passwords are configured. Exploitation requires physical possession, disassembly of a Cloud Key Gen2 or Gen2 Plus, and connection to its labeled UART pads; the consequence is complete device control.

CVSS severity6.8
Medium
EPSS probability0.36%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper access control in Ubiquiti UniFi Cloud Key firmware 1.1.10 and earlier allows local users to gain root access via UART. The serial console exposes a root shell without authentication, even when application and management passwords are configured. Exploitation requires physical possession, disassembly of a Cloud Key Gen2 or Gen2 Plus, and connection to its labeled UART pads; the consequence is complete device control.

The record

CVE
CVE-2020-8157
Published
May 2, 2020
Updated
Aug 4, 2024
Vendor
Ubiquiti
Product
UniFi Cloud Key Firmware
Classifications
CWE-284, T1200
Attack vector
physical
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 2, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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=Fixed in v1.1.11

What conditions does exploitation require?

Attack vectorphysical
Required privilegesunauthenticated

What is affected?

Ubiquiti · UniFi Cloud Key Firmwareversion=Fixed in v1.1.11

Published CVSS scores

6.8UbiquitiCVSS:3.0/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:H/RL:O/RC:C
6.8NVDCVSS:3.0/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorphysical
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-284Improper Access Control - Generic
T1200Exploitation of Physical Access

Public exploit references

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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