# CVE-2022-27646: Memory corruption in R6700v3

> A stack-based buffer overflow in the circled daemon allows network-adjacent attackers to execute arbitrary code as root, bypassing authentication.

- **Severity:** High 8.0 (`CVSS:3.0/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 29 Mar 2023
- **Updated:** 18 Feb 2025
- **Also known as:** GHSA-qjg8-7gjq-vxf4

## What is CVE-2022-27646?

CVE-2022-27646 is a high-severity memory corruption vulnerability in Netgear R6400 Firmware, published on 29 Mar 2023. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of NETGEAR R6700v3 1.0.4.120_10.0.91 routers. Although authentication is required to exploit this vulnerability, the existing authentication mechanism can be bypassed. The specific flaw exists within the circled daemon. A crafted circleinfo.txt file can trigger an overflow of a fixed-length stack-based buffer. An attacker can leverage this vulnerability to execute code in the context of root. Was ZDI-CAN-15879.

Weakness: CWE-121 (Stack-based Buffer Overflow)

## Which versions are affected by CVE-2022-27646?

It affects 24 products.


Products: Netgear Cbr40 Firmware, Netgear Lbr1020 Firmware, Netgear Lbr20 Firmware, Netgear R6400 Firmware, Netgear R6700 Firmware, Netgear R6900p Firmware, Netgear R7000 Firmware, Netgear R7000p Firmware, Netgear R7850 Firmware, Netgear R7960p Firmware, Netgear R8000 Firmware, Netgear R8000p Firmware, Netgear Rax200 Firmware, Netgear Rax75 Firmware, Netgear Rax80 Firmware, Netgear Rbr10 Firmware, Netgear Rbr20 Firmware, Netgear Rbr40 Firmware, Netgear Rbr50 Firmware, Netgear Rbs10 Firmware and 4 more.

## How do I fix CVE-2022-27646?

No fix has been published for CVE-2022-27646 yet. Limit exposure of the affected software until one is available.

## Is CVE-2022-27646 being exploited?

There is no known exploitation of CVE-2022-27646 in the wild and no public exploit code.

Public exploit code:

- Demonstrate some functionalities of Morion by generating an exploit for CVE-2022-27646 (stack buffer overflow on Netgear R6700v3 routers). (github_poc): https://github.com/cyber-defence-campus/netgear_r6700v3_circled

## Other vulnerabilities in Netgear R6400 Firmware

- [CVE-2021-45630](https://insights.sbomify.com/CVE-2021-45630/): Command injection in n/a (critical 10.0)
- [CVE-2023-36187](https://insights.sbomify.com/CVE-2023-36187/): Memory corruption in n/a (critical 9.8)
- [CVE-2021-45617](https://insights.sbomify.com/CVE-2021-45617/): Command injection in n/a (critical 9.8)
- [CVE-2021-45504](https://insights.sbomify.com/CVE-2021-45504/): Auth bypass in n/a (critical 9.6)
- [CVE-2021-45507](https://insights.sbomify.com/CVE-2021-45507/): Auth bypass in n/a (critical 9.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-27646 and fix it if it is affected.

What it is: CVE-2022-27646 is a high-severity memory corruption vulnerability in Netgear R6400 Firmware, published on 29 Mar 2023. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2022-27646 in the wild and no public exploit code.

Affected product: Netgear R6400 Firmware. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2022-27646/ (Markdown: https://insights.sbomify.com/CVE-2022-27646/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-27646
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-27646
- OSV: https://osv.dev/vulnerability/CVE-2022-27646

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-27646/
Summaries are generated and may contain mistakes; the official description above is the record.