CVE-2021-31505

Name: CVE-2021-31505
Creator: NVD / NIST
Published: 2021-06-29T15:15:18.993+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.8/10EPSS 0.55%

Last modified Jun 17, 2026

CVE-2021-31505 is a medium-severity vulnerability rated 6.8/10 on the CVSS scale. This vulnerability allows attackers with physical access to escalate privileges on affected installations of Arlo Q Plus 1.9.0.3_278. Authentication is not required to exploit this vulnerability. EPSS estimates a 0.55% chance of exploitation in the next 30 days.

Description

This vulnerability allows attackers with physical access to escalate privileges on affected installations of Arlo Q Plus 1.9.0.3_278. Authentication is not required to exploit this vulnerability. The specific flaw exists within the SSH service. The device can be booted into a special operation mode where hard-coded credentials are accepted for SSH authentication. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of root. Was ZDI-CAN-12890.

Metrics

CVSS 3.1

6.8/10

CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

0.55%

41.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-798

Affected Software

Vendor	Product	Versions
Arlo	Q Plus Firmware	1.9.0.3_278

References

https://kb.arlo.com/000062592/Security-Advisory-for-Arlo-Q-Plus-SSH-Use-of-Hard-coded-Credentials-Allowing-Privilege-EscalationVendor Advisory
https://www.zerodayinitiative.com/advisories/ZDI-21-683/Third Party Advisory, VDB Entry
https://kb.arlo.com/000062592/Security-Advisory-for-Arlo-Q-Plus-SSH-Use-of-Hard-coded-Credentials-Allowing-Privilege-EscalationVendor Advisory
https://www.zerodayinitiative.com/advisories/ZDI-21-683/Third Party Advisory, VDB Entry

Timeline

Published: Jun 29, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-31505?

How severe is CVE-2021-31505?

CVE-2021-31505 has a CVSS score of 6.8/10 (MEDIUM severity). The EPSS model estimates a 0.55% probability of exploitation in the next 30 days.

How do I fix CVE-2021-31505?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-31505?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST