How severe is CVE-2021-27252?

CVE-2021-27252 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-27252 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (62nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-27252?

CVE-2021-27252 primarily affects Netgear Br200 Firmware. In total, 43 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-27252?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-27252 published?

CVE-2021-27252 was published on 2021-04-14 and last updated on 2026-06-17.

CVE-2021-27252

CVE-2021-27252 is a high-severity vulnerability in Netgear Br200 Firmware with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-78.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 8.3
EPSS exploit prediction: 1% (62nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-78
Affected product: Netgear Br200 Firmware
Published: 2021-04-14
Last modified: 2026-06-17

Description

This vulnerability allows network-adjacent 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 handling of the vendor_specific DHCP opcode. The issue results from the lack of proper validation of a user-supplied string before using it to execute a system call. An attacker can leverage this vulnerability to execute code in the context of root. Was ZDI-CAN-12216.

Frequently asked questions

What is CVE-2021-27252?: This vulnerability allows network-adjacent 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 handling of the vendor_specific DHCP opcode. The issue results from the lack of proper validation of a user-supplied string before using it to execute a system call. An attacker can leverage this vulnerability to execute code in the context of root. Was ZDI-CAN-12216.
How severe is CVE-2021-27252?: CVE-2021-27252 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-27252 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (62nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-27252?: CVE-2021-27252 primarily affects Netgear Br200 Firmware. In total, 43 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-27252?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-27252 published?: CVE-2021-27252 was published on 2021-04-14 and last updated on 2026-06-17.

References

Affected products (43)

cpe:2.3:o:netgear:br200_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:br500_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:d7800_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:ex6100v2_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:ex6150_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:ex6250_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:ex6400_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:ex6400v2_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:ex6410_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:ex6420_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:ex7300_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:ex7300v2_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:ex7320_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:ex7700_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:ex8000_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:lbr20_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:r7800_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:r8900_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:r9000_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbk12_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbk13_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbk14_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbk15_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbk20_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbk23_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbk40_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbk43_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbk43s_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbk44_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbk50_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbk53_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbr10_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbr20_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbr40_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbr50_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbs10_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbs20_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbs40_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbs50_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbs50y_firmware:*:*:*:*:*:*:*:*

More vulnerabilities in Netgear Br200 Firmware

CVE-2021-27253 — High (CVSS 8.8): This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of NETGEAR…
CVE-2021-27251 — High (CVSS 8.8): This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of NETGEAR…
CVE-2021-27256 — High (CVSS 8.8): This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of NETGEAR…
CVE-2021-27255 — High (CVSS 8.8): This vulnerability allows remote attackers to execute arbitrary code on affected installations of NETGEAR R7800…
CVE-2021-27254 — High (CVSS 8.8): This vulnerability allows network-adjacent attackers to bypass authentication on affected installations of NETGEAR…
CVE-2021-27257 — Medium (CVSS 6.5): This vulnerability allows network-adjacent attackers to compromise the integrity of downloaded information on affected…

All CVEs affecting Netgear Br200 Firmware →

Other CWE-78 (OS Command Injection) vulnerabilities

CVE-2026-56004 — Critical (CVSS 10.0): A shellcode injection in the mercurial handler of the obs tar_scm source service before version 0.12.4 could be used by…
CVE-2026-56415 — Critical (CVSS 10.0): Storage Concentrator (SC & SCVM) contains a command injection vulnerability within the debug.pl script that is…
CVE-2026-56413 — Critical (CVSS 10.0): Storage Concentrator (SC & SCVM) contains a command injection vulnerability in the ms_service.pl service, which listens…
CVE-2026-49869 — Critical (CVSS 10.0): Kestra is an open-source, event-driven orchestration platform. Prior to 1.0.45 and 1.3.21, AuthenticationFilter in…
CVE-2026-49261 — Critical (CVSS 10.0): MariaDB server is a community developed fork of MySQL server. Versions 10.6.1 through 10.6.26, 10.11.1 through…
CVE-2026-10520 — Critical (CVSS 10.0): An OS Command Injection vulnerability in Ivanti Sentry before the R10.5.2, R10.6.2 and R10.7.1 versions allows a…

Browse all CWE-78 (OS Command Injection) vulnerabilities →