# What is CVE-2020-27861? > CVE-2020-27861 is a high-severity flaw (CVSS 8.8) in Cbk40 Firmware from Netgear, published on 12 February 2021. It is not on the list of flaws known to be exploited today. The latest forecast puts its chance of use in the next 30 days at 2.0%. If you run an affected version, plan in the vendor’s fix. Canonical page: https://www.precursorintelligence.com/what-is/cve-2020-27861 ## At a glance - **Verdict:** Plan it in. No sign of exploitation and a low forecast. Patch it in your normal update cycle. - **Precursor Intelligence risk score:** 48 out of 100 (Medium); action: Plan remediation. Kept up to date as the evidence changes. - **Severity:** High (CVSS 8.8 out of 10) - **Known to be exploited:** No, not on the list of flaws known to be exploited today - **Chance of use in the next 30 days:** 2.0% (latest exploit-likelihood forecast) - **Published:** 12 February 2021 - **Record last updated:** 23 March 2021 - **Main product:** Cbk40 Firmware from Netgear - **Affected products:** 71 ## What is CVE-2020-27861? In plain terms An attacker has to be on the same local network without logging in, and nobody has to click anything. If it works, the attacker can read data, change data and take it offline. ### The 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. ### What kind of flaw is it? - CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') ### How an attack on it works - Where an attacker can be: On the same local network - How hard it is to pull off: Easy: no special conditions - Login needed first: No login needed - Does someone have to click: No, nobody has to do anything - What an attacker gets: Can read data, change data and take it offline Severity vector: `CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H` ## Is CVE-2020-27861 being exploited? Not that we know of It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 2.0%. That can change at any time, which is why we keep watching. Exploit likelihood over the last 7 days: 2.0%, 2.0%, 2.0%, 2.0%, 2.0%, 2.0%, 2.0%. ### Timeline - 12 February 2021: Published - 23 March 2021: Record last updated ### How Precursor Intelligence ranks it CVE-2020-27861 scores **48 out of 100 (Medium)**, with the action "Plan remediation". Every published flaw gets a risk score from 0 to 100, kept up to date as the evidence changes. Four things go into the score, from the one that counts most to the ones that count less: - Evidence it is being exploited: biggest factor - How severe it is: strong factor - How widely exposed it is: key context - Real threat activity around it: key context 85 and above is Critical. Anything confirmed as exploited is always marked for an emergency patch, whatever its score. When this flaw matches software you track, it lands in your list with its score and the reasons behind it. ## Who is affected by CVE-2020-27861? The published record lists 71 products. Versions are as published: "before 2.6.1.38" means every version up to, but not including, 2.6.1.38. - [Cbk40 Firmware](https://www.precursorintelligence.com/product/netgear/cbk40_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.38 - [Cbk40](https://www.precursorintelligence.com/product/netgear/cbk40) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Hardware): version not specified - [Cbk43](https://www.precursorintelligence.com/product/netgear/cbk43) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Hardware): version not specified - [Cbk43 Firmware](https://www.precursorintelligence.com/product/netgear/cbk43_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.38 - [Cbr40](https://www.precursorintelligence.com/product/netgear/cbr40) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Hardware): version not specified - [Cbr40 Firmware](https://www.precursorintelligence.com/product/netgear/cbr40_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.38 - [Ex6200](https://www.precursorintelligence.com/product/netgear/ex6200) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Hardware): v2 - [Ex6200 Firmware](https://www.precursorintelligence.com/product/netgear/ex6200_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 1.0.1.82 - [Ex7700](https://www.precursorintelligence.com/product/netgear/ex7700) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Hardware): version not specified - [Ex7700 Firmware](https://www.precursorintelligence.com/product/netgear/ex7700_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 1.0.0.210 - [Ex8000](https://www.precursorintelligence.com/product/netgear/ex8000) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Hardware): version not specified - [Ex8000 Firmware](https://www.precursorintelligence.com/product/netgear/ex8000_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 1.0.1.224 - [Rbk12](https://www.precursorintelligence.com/product/netgear/rbk12) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Hardware): version not specified - [Rbk12 Firmware](https://www.precursorintelligence.com/product/netgear/rbk12_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.44 - [Rbk13](https://www.precursorintelligence.com/product/netgear/rbk13) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Hardware): version not specified - [Rbk13 Firmware](https://www.precursorintelligence.com/product/netgear/rbk13_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.44 - [Rbk14](https://www.precursorintelligence.com/product/netgear/rbk14) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Hardware): version not specified - [Rbk14 Firmware](https://www.precursorintelligence.com/product/netgear/rbk14_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.44 - [Rbk15](https://www.precursorintelligence.com/product/netgear/rbk15) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Hardware): version not specified - [Rbk15 Firmware](https://www.precursorintelligence.com/product/netgear/rbk15_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.44 - [Rbk20](https://www.precursorintelligence.com/product/netgear/rbk20) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Hardware): version not specified - [Rbk20 Router Firmware](https://www.precursorintelligence.com/product/netgear/rbk20_router_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.36 - [Rbk20 Satellite Firmware](https://www.precursorintelligence.com/product/netgear/rbk20_satellite_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.38 - [Rbk20w](https://www.precursorintelligence.com/product/netgear/rbk20w) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Hardware): version not specified - [Rbk20w Firmware](https://www.precursorintelligence.com/product/netgear/rbk20w_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.36 - [Rbk22](https://www.precursorintelligence.com/product/netgear/rbk22) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Hardware): version not specified - [Rbk22 Router Firmware](https://www.precursorintelligence.com/product/netgear/rbk22_router_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.36 - [Rbk22 Satellite Firmware](https://www.precursorintelligence.com/product/netgear/rbk22_satellite_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.38 - [Rbk23](https://www.precursorintelligence.com/product/netgear/rbk23) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Hardware): version not specified - [Rbk23 Router Firmware](https://www.precursorintelligence.com/product/netgear/rbk23_router_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.36 - [Rbk23 Satellite Firmware](https://www.precursorintelligence.com/product/netgear/rbk23_satellite_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.38 - [Rbk23w](https://www.precursorintelligence.com/product/netgear/rbk23w) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Hardware): version not specified - [Rbk23w Firmware](https://www.precursorintelligence.com/product/netgear/rbk23w_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.36 - [Rbk30](https://www.precursorintelligence.com/product/netgear/rbk30) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Hardware): version not specified - [Rbk30 Firmware](https://www.precursorintelligence.com/product/netgear/rbk30_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.36 - [Rbk33](https://www.precursorintelligence.com/product/netgear/rbk33) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Hardware): version not specified - [Rbk33 Firmware](https://www.precursorintelligence.com/product/netgear/rbk33_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.36 - [Rbk40](https://www.precursorintelligence.com/product/netgear/rbk40) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Hardware): version not specified - [Rbk40 Router Firmware](https://www.precursorintelligence.com/product/netgear/rbk40_router_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.36 - [Rbk40 Satellite Firmware](https://www.precursorintelligence.com/product/netgear/rbk40_satellite_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.38 - [Rbk43](https://www.precursorintelligence.com/product/netgear/rbk43) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Hardware): version not specified - [Rbk43 Router Firmware](https://www.precursorintelligence.com/product/netgear/rbk43_router_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.36 - [Rbk43 Satellite Firmware](https://www.precursorintelligence.com/product/netgear/rbk43_satellite_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.38 - [Rbk43s](https://www.precursorintelligence.com/product/netgear/rbk43s) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Hardware): version not specified - [Rbk43s Router Firmware](https://www.precursorintelligence.com/product/netgear/rbk43s_router_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.36 - [Rbk43s Satellite Firmware](https://www.precursorintelligence.com/product/netgear/rbk43s_satellite_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.38 - [Rbk44](https://www.precursorintelligence.com/product/netgear/rbk44) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Hardware): version not specified - [Rbk44 Router Firmware](https://www.precursorintelligence.com/product/netgear/rbk44_router_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.36 - [Rbk44 Satellite Firmware](https://www.precursorintelligence.com/product/netgear/rbk44_satellite_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.38 - [Rbk50](https://www.precursorintelligence.com/product/netgear/rbk50) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Hardware): version not specified - [Rbk50 Firmware](https://www.precursorintelligence.com/product/netgear/rbk50_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.40 - [Rbk50v](https://www.precursorintelligence.com/product/netgear/rbk50v) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Hardware): version not specified - [Rbk50v Firmware](https://www.precursorintelligence.com/product/netgear/rbk50v_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.40 - [Rbk52w](https://www.precursorintelligence.com/product/netgear/rbk52w) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Hardware): version not specified - [Rbk52w Firmware](https://www.precursorintelligence.com/product/netgear/rbk52w_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.40 - [Rbr10](https://www.precursorintelligence.com/product/netgear/rbr10) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Hardware): version not specified - [Rbr10 Firmware](https://www.precursorintelligence.com/product/netgear/rbr10_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.44 - [Rbr20](https://www.precursorintelligence.com/product/netgear/rbr20) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Hardware): version not specified - [Rbr20 Firmware](https://www.precursorintelligence.com/product/netgear/rbr20_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.36 - [Rbr40](https://www.precursorintelligence.com/product/netgear/rbr40) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Hardware): version not specified - [Rbr40 Firmware](https://www.precursorintelligence.com/product/netgear/rbr40_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.36 - [Rbr50](https://www.precursorintelligence.com/product/netgear/rbr50) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Hardware): version not specified - [Rbr50 Firmware](https://www.precursorintelligence.com/product/netgear/rbr50_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.40 - [Rbs10](https://www.precursorintelligence.com/product/netgear/rbs10) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Hardware): version not specified - [Rbs10 Firmware](https://www.precursorintelligence.com/product/netgear/rbs10_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.44 - [Rbs20](https://www.precursorintelligence.com/product/netgear/rbs20) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Hardware): version not specified - [Rbs20 Firmware](https://www.precursorintelligence.com/product/netgear/rbs20_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.38 - [Rbs40](https://www.precursorintelligence.com/product/netgear/rbs40) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Hardware): version not specified - [Rbs40 Firmware](https://www.precursorintelligence.com/product/netgear/rbs40_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.38 - [Rbs50](https://www.precursorintelligence.com/product/netgear/rbs50) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Hardware): version not specified - [Rbs50 Firmware](https://www.precursorintelligence.com/product/netgear/rbs50_firmware) by [Netgear](https://www.precursorintelligence.com/vendors/netgear) (Operating system): before 2.6.1.40 ## How do I fix CVE-2020-27861? 1. **Check whether you run it.** Compare your versions with the affected products above. Not sure what you run? Precursor Intelligence can work it out from your public website, or you can pick it from a list. 2. **Apply the vendor’s fix.** Install the update named in the vendor’s advisory. We’ve put the advisory first in the list. 3. **If you can’t patch today.** Follow any mitigation the vendor publishes, and limit who can reach the affected system from the internet until the update is in. 4. **Keep an eye on it.** Track the product and we tell you as soon as we spot this flaw on the list of exploited flaws, or a jump in its exploit likelihood. ### References - [kb.netgear.com](https://kb.netgear.com/000062507/Security-Advisory-for-Unauthenticated-Command-Injection-Vulnerability-on-Some-Extenders-and-Orbi-WiFi-Systems) (Vendor advisory) - [zerodayinitiative.com](https://www.zerodayinitiative.com/advisories/ZDI-20-1430/) (Third-party advisory, Vulnerability database) ## Questions ### What is CVE-2020-27861? CVE-2020-27861 is a high-severity flaw in Cbk40 Firmware from Netgear, published on 12 February 2021. An attacker has to be on the same local network without logging in, and nobody has to click anything. If it works, the attacker can read data, change data and take it offline. ### How serious is CVE-2020-27861? It scores 8.8 out of 10 on the CVSS severity scale, which is high. Our risk score for CVE-2020-27861 is 48 out of 100, which is Medium. Its action is "Plan remediation". No sign of exploitation and a low forecast. Patch it in your normal update cycle. ### Is CVE-2020-27861 being exploited? It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 2.0%. That can change at any time, which is why we keep watching. ### Which versions does CVE-2020-27861 affect? For Cbk40 Firmware from Netgear: before 2.6.1.38. The record lists 71 products in all, each with its versions, under "Who is affected" on this page. ### How do I fix CVE-2020-27861? Install the update the vendor names in its advisory, linked first under "How do I fix" on this page. If you can't patch today, follow the vendor's mitigation and limit who can reach the affected system from the internet. ## Does CVE-2020-27861 affect you? Precursor Intelligence keeps checking for you: - **Tell us what you run.** Pick your software from a list, or let us work it out from your website. - **We match it to every flaw.** Over 400,000 published flaws, checked against your list. - **Ranked by real-world risk.** Every flaw gets a 0 to 100 risk score, kept up to date, led by evidence criminals are using it. - **Told as soon as we know.** An alert by email, in the app or by webhook to your own tools. Start free (no card, nothing to install): https://www.precursorintelligence.com/register Book a demo: https://www.precursorintelligence.com/contact