HOMEVULNERABILITIESCVE-2020-27861
HIGH

CVE-2020-27861

CWE-78Published: February 12, 2021· Updated: Jun 17, 2026

8.8
CVSS v3.1

Official Description

This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of NETGEAR Orbi 2.5.1.16 routers. Authentication is not required to exploit this vulnerability. The specific flaw exists within the UA_Parser utility. A crafted Host Name option in a DHCP request can trigger execution of a system call composed from a user-supplied string. An attacker can leverage this vulnerability to execute code in the context of root. Was ZDI-CAN-11076.

NVD Source

Technical Analysis

CVE-2020-27861 requires adjacent network access, limiting remote exploitation but still posing risk in shared or local network environments.

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 8.8.

CVSS v3.1 Vector Breakdown

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

Affected Vendors & Products

netgear71 product(s)
cbk40 firmwarecbk40cbk43 firmwarecbk43cbr40 firmwarecbr40ex6200 firmwareex6200ex7700 firmwareex7700ex8000 firmwareex8000+59
Source: NVD CPE · 71 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.netgear.com/000062507/Security-Advisory-for-Unauthenticated-Command-Injection-Vulnerability-on-Some-Extenders-and-Orbi-WiFi-Systems
ADVISORYhttps://www.zerodayinitiative.com/advisories/ZDI-20-1430/
ADVISORYhttps://kb.netgear.com/000062507/Security-Advisory-for-Unauthenticated-Command-Injection-Vulnerability-on-Some-Extenders-and-Orbi-WiFi-Systems
ADVISORYhttps://www.zerodayinitiative.com/advisories/ZDI-20-1430/

All References (4)

→
https://kb.netgear.com/000062507/Security-Advisory-for-Unauthenticated-Command-Injection-Vulnerability-on-Some-Extenders-and-Orbi-WiFi-SystemsVendor Advisory
→
https://www.zerodayinitiative.com/advisories/ZDI-20-1430/Third Party Advisory · VDB Entry
→
https://kb.netgear.com/000062507/Security-Advisory-for-Unauthenticated-Command-Injection-Vulnerability-on-Some-Extenders-and-Orbi-WiFi-SystemsVendor Advisory
→
https://www.zerodayinitiative.com/advisories/ZDI-20-1430/Third Party Advisory · VDB Entry

Quick Facts

CVE IDCVE-2020-27861
CVSS Score8.8 / 10
SeverityHIGH
WeaknessCWE-78
CISA KEVNo
Affected1 vendor(s)
PublishedFeb 12, 2021

Related CVEs (CWE-78)

CVE-2013-4781
10.0
CVE-2014-2874
10.0
CVE-2012-6593
10.0
CVE-2012-2976
10.0
CVE-2012-6592
10.0
CVE-2012-6601
10.0

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2020-27861 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.COM. CVE data is provided under the NVD usage policy.
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