HOMEVULNERABILITIESCVE-2021-27254
HIGH

CVE-2021-27254

CWE-259Published: March 5, 2021· Updated: Jun 17, 2026

8.8
CVSS v3.1

Official Description

This vulnerability allows network-adjacent attackers to bypass authentication on affected installations of NETGEAR R7800. Authentication is not required to exploit this vulnerability. The specific flaw exists within the apply_save.cgi endpoint. This issue results from the use of hard-coded encryption key. An attacker can leverage this vulnerability to execute arbitrary code in the context of root. Was ZDI-CAN-12287.

NVD Source

Technical Analysis

CVE-2021-27254 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

netgear86 product(s)
br200 firmwarebr200br500 firmwarebr500d7800 firmwared7800ex6100v2 firmwareex6100v2ex6150v2 firmwareex6150v2ex6250 firmwareex6250+74
Source: NVD CPE · 86 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

PATCHhttps://kb.netgear.com/000062883/Security-Advisory-for-Multiple-Vulnerabilities-on-Some-Routers-Satellites-and-Extenders
PATCHhttps://kb.netgear.com/000062883/Security-Advisory-for-Multiple-Vulnerabilities-on-Some-Routers-Satellites-and-Extenders
ADVISORYhttps://www.zerodayinitiative.com/advisories/ZDI-21-252/
ADVISORYhttps://www.zerodayinitiative.com/advisories/ZDI-21-252/

All References (4)

→
https://kb.netgear.com/000062883/Security-Advisory-for-Multiple-Vulnerabilities-on-Some-Routers-Satellites-and-ExtendersPatch · Vendor Advisory
→
https://www.zerodayinitiative.com/advisories/ZDI-21-252/Third Party Advisory · VDB Entry
→
https://kb.netgear.com/000062883/Security-Advisory-for-Multiple-Vulnerabilities-on-Some-Routers-Satellites-and-ExtendersPatch · Vendor Advisory
→
https://www.zerodayinitiative.com/advisories/ZDI-21-252/Third Party Advisory · VDB Entry

Quick Facts

CVE IDCVE-2021-27254
CVSS Score8.8 / 10
SeverityHIGH
WeaknessCWE-259
CISA KEVNo
Affected1 vendor(s)
PublishedMar 5, 2021

Related CVEs (CWE-259)

CVE-2014-2363
10.0
CVE-2012-5862
10.0
CVE-2024-32741
10.0
CVE-2017-6022
9.8
CVE-2022-22144
9.8
CVE-2021-34601
9.8

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-27254 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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