Cyber Resilience

CVE-2021-27255

High

Published: 05 March 2021

Published
05 March 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 8.8 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0167 82.5th percentile
Risk Priority 19 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-27255 is a high-severity Missing Authentication for Critical Function (CWE-306) vulnerability in Netgear Br200 Firmware. Its CVSS base score is 8.8 (High).

Operationally, ranked in the top 17.5% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

This vulnerability allows remote attackers to execute arbitrary code on affected installations of NETGEAR R7800 firmware version 1.0.2.76. Authentication is not required to exploit this vulnerability. The specific flaw exists within the refresh_status.aspx endpoint. The issue results from a lack…

more

of authentication required to start a service on the server. An attacker can leverage this vulnerability to execute code in the context of root. Was ZDI-CAN-12360.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

netgear
br200 firmware
≤ 5.10.0.5
netgear
br500 firmware
≤ 5.10.0.5
netgear
d7800 firmware
≤ 1.0.1.60
netgear
ex6100v2 firmware
≤ 1.0.1.98
netgear
ex6150v2 firmware
≤ 1.0.1.98
netgear
ex6250 firmware
≤ 1.0.0.134
netgear
ex6400 firmware
≤ 1.0.2.158
netgear
ex6400v2 firmware
≤ 1.0.0.134
netgear
ex6410 firmware
≤ 1.0.0.134
netgear
ex6420 firmware
≤ 1.0.0.134
+33 more product configuration(s) — see NVD for full list

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-306

Requires established identification and authentication to unlock, mitigating missing authentication for continued system access.

addresses: CWE-306

Requiring identification and rationale for actions allowed without authentication ensures critical functions are not left unprotected by forcing review of authentication requirements.

addresses: CWE-306

Authorizing mobile device connections to organizational systems ensures authentication is performed for this critical access function.

addresses: CWE-306

Guarantees critical functions are protected by mandatory invocation of the access control mechanism.

addresses: CWE-306

Auditing sessions makes it possible to detect access to critical functions without required authentication.

addresses: CWE-306

The assessment process confirms authentication is present and effective for critical functions, preventing exploitation from missing authentication.

addresses: CWE-306

Certification assesses that critical functions have required authentication controls in place.

addresses: CWE-306

Disabling non-essential functions and services eliminates the need to secure them, reducing exposure from missing authentication on unnecessary components.

References