# CVE-2022-26531: Memory corruption in ATP series firmware

> A local authenticated attacker can cause a system crash or buffer overflow in Zyxel network devices via crafted CLI commands.

- **Severity:** Medium 6.1 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/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:** 24 May 2022
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-rg7w-p5vw-jmcc

## What is CVE-2022-26531?

CVE-2022-26531 is a medium-severity memory corruption vulnerability in Zyxel ATP series firmware, published on 24 May 2022. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Multiple improper input validation flaws were identified in some CLI commands of Zyxel USG/ZyWALL series firmware versions 4.09 through 4.71, USG FLEX series firmware versions 4.50 through 5.21, ATP series firmware versions 4.32 through 5.21, VPN series firmware versions 4.30 through 5.21, NSG series firmware versions 1.00 through 1.33 Patch 4, NXC2500 firmware version 6.10(AAIG.3) and earlier versions, NAP203 firmware version 6.25(ABFA.7) and earlier versions, NWA50AX firmware version 6.25(ABYW.5) and earlier versions, WAC500 firmware version 6.30(ABVS.2) and earlier versions, and WAX510D firmware version 6.30(ABTF.2) and earlier versions, that could allow a local authenticated attacker to cause a buffer overflow or a system crash via a crafted payload.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2022-26531?

It affects 65 products.


Products: Zyxel Atp100 Firmware, Zyxel Atp100w Firmware, Zyxel Atp200 Firmware, Zyxel Atp500 Firmware, Zyxel Atp700 Firmware, Zyxel Atp800 Firmware, Zyxel Nap203 Firmware, Zyxel Nap303 Firmware, Zyxel Nap353 Firmware, Zyxel Nsg100 Firmware, Zyxel Nsg300 Firmware, Zyxel Nsg50 Firmware, Zyxel Nwa110ax Firmware, Zyxel Nwa1123-Ac-Hd Firmware, Zyxel Nwa1123-Ac-Pro Firmware, Zyxel Nwa1123acv3 Firmware, Zyxel Nwa1302-Ac Firmware, Zyxel Nwa210ax Firmware, Zyxel Nwa50ax Firmware, Zyxel Nwa5123-Ac-Hd Firmware and 45 more.

## How do I fix CVE-2022-26531?

No fix has been published for CVE-2022-26531 yet. Limit exposure of the affected software until one is available.

## Is CVE-2022-26531 being exploited?

There is no known exploitation of CVE-2022-26531 in the wild and no public exploit code.

## Other vulnerabilities in Zyxel ATP series firmware

- [CVE-2023-33009](https://insights.sbomify.com/CVE-2023-33009/): Zyxel Multiple Firewalls Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2023-33010](https://insights.sbomify.com/CVE-2023-33010/): Zyxel Multiple Firewalls Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2023-28771](https://insights.sbomify.com/CVE-2023-28771/): Zyxel Multiple Firewalls OS Command Injection (critical 9.8, exploited in the wild)
- [CVE-2022-30525](https://insights.sbomify.com/CVE-2022-30525/): Zyxel Multiple Firewalls OS Command Injection (critical 9.8, exploited in the wild)
- [CVE-2020-29583](https://insights.sbomify.com/CVE-2020-29583/): Zyxel Multiple Products Use of Hard-Coded Credentials (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-26531 and fix it if it is affected.

What it is: CVE-2022-26531 is a medium-severity memory corruption vulnerability in Zyxel ATP series firmware, published on 24 May 2022. 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-2022-26531 in the wild and no public exploit code.

Affected product: Zyxel ATP series 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-2022-26531/ (Markdown: https://insights.sbomify.com/CVE-2022-26531/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-26531
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-26531
- OSV: https://osv.dev/vulnerability/CVE-2022-26531

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-26531/
Summaries are generated and may contain mistakes; the official description above is the record.