How severe is CVE-2020-27861?

CVE-2020-27861 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-2020-27861 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (80th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-27861?

CVE-2020-27861 primarily affects Netgear Cbk40 Firmware. In total, 39 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-27861?

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-2020-27861 published?

CVE-2020-27861 was published on 2021-02-12 and last updated on 2026-06-17.

CVE-2020-27861

CVE-2020-27861 is a high-severity vulnerability in Netgear Cbk40 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: 2% (80th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-78
Affected product: Netgear Cbk40 Firmware
Published: 2021-02-12
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2020-27861?: 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.
How severe is CVE-2020-27861?: CVE-2020-27861 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-2020-27861 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (80th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-27861?: CVE-2020-27861 primarily affects Netgear Cbk40 Firmware. In total, 39 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-27861?: 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-2020-27861 published?: CVE-2020-27861 was published on 2021-02-12 and last updated on 2026-06-17.

References

Affected products (39)

cpe:2.3:o:netgear:cbk40_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:cbk43_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:cbr40_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:ex6200_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:ex7700_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:ex8000_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:rbr10_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbs10_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbk20w_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbk23w_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbk20_router_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbk20_satellite_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbk22_router_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbk22_satellite_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbk23_router_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbk23_satellite_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbr20_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbs20_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbk30_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbk33_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbk40_router_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbk40_satellite_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbk43_router_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbk43_satellite_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbk43s_router_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbk43s_satellite_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbk44_router_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbk44_satellite_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbr40_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbs40_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbk50_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbk50v_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbk52w_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbr50_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:rbs50_firmware:*:*:*:*:*:*:*:*

More vulnerabilities in Netgear Cbk40 Firmware

CVE-2020-35795 — Critical (CVSS 9.8): Certain NETGEAR devices are affected by a buffer overflow by an unauthenticated attacker. This affects AC2100 before…
CVE-2020-35800 — Critical (CVSS 9.4): Certain NETGEAR devices are affected by incorrect configuration of security settings. This affects AC2100 before…
CVE-2024-28340 — High (CVSS 7.5): An information leak in the currentsetting.htm component of Netgear CBR40 2.5.0.28, Netgear CBK40 2.5.0.28, and Netgear…
CVE-2024-28339 — Medium (CVSS 5.4): An information leak in the debuginfo.htm component of Netgear CBR40 2.5.0.28, Netgear CBK40 2.5.0.28, and Netgear CBK43…

All CVEs affecting Netgear Cbk40 Firmware →

Other CWE-78 (OS Command Injection) vulnerabilities

CVE-2026-19188 — Critical (CVSS 10.0): A critical OS command injection vulnerability has been identified in the Haiwell IoT Cloud HMI Gateway product. The…
CVE-2026-48362 — Critical (CVSS 10.0): ColdFusion is affected by an Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')…
CVE-2026-16812 — Critical (CVSS 10.0): VeloCloud Orchestrator (VCO) on-prem has a security issue where this issue may allow a remote attacker to access…
CVE-2026-6516 — Critical (CVSS 10.0): Zohocorp ManageEngine ADAudit Plus versions before 8606 are affected by Unauthenticated Remote code execution due to…
CVE-2026-46339 — Critical (CVSS 10.0): 9Router is an AI router & token saver. From 0.4.30 until 0.4.37, 9Router's src/proxy.js middleware did not protect…
CVE-2026-59726 — Critical (CVSS 10.0): Ruflo is an agent meta-harness for Claude Code and Codex. Prior to 3.16.3, ruflo's default docker-compose deployment…

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