HOMEVULNERABILITIESCVE-2021-31505
MEDIUM

CVE-2021-31505

CWE-798Published: June 29, 2021· Updated: Jun 17, 2026

6.8
CVSS v3.1

Official 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.

NVD Source

Technical Analysis

CVE-2021-31505 requires local access, meaning attackers must already have a foothold on the target system.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 6.8.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorPhysical
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Vendors & Products

arlo2 product(s)
q plus firmwareq plus
Source: NVD CPE · 2 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://kb.arlo.com/000062592/Security-Advisory-for-Arlo-Q-Plus-SSH-Use-of-Hard-coded-Credentials-Allowing-Privilege-Escalation
ADVISORYhttps://www.zerodayinitiative.com/advisories/ZDI-21-683/
ADVISORYhttps://kb.arlo.com/000062592/Security-Advisory-for-Arlo-Q-Plus-SSH-Use-of-Hard-coded-Credentials-Allowing-Privilege-Escalation
ADVISORYhttps://www.zerodayinitiative.com/advisories/ZDI-21-683/

All References (4)

→
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

Quick Facts

CVE IDCVE-2021-31505
CVSS Score6.8 / 10
SeverityMEDIUM
WeaknessCWE-798
CISA KEVNo
Affected1 vendor(s)
PublishedJun 29, 2021

Related CVEs (CWE-798)

CVE-2017-2343
10.0
CVE-2013-3542
10.0
CVE-2026-45336
10.0
CVE-2014-9198
10.0
CVE-2018-0222
10.0
CVE-2020-6963
10.0

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-31505 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWatch. CVE data is provided under the NVD usage policy.
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