# CVE-2018-5455: Auth bypass in Moxa OnCell G3100-HSPA Series

> Attackers can bypass authentication via brute force on weak cookie validation to gain unauthorized access to Moxa OnCell device functions.

- **Severity:** Critical 9.8 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 5 Mar 2018
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-xp2r-3x9c-rvxq

## What is CVE-2018-5455?

CVE-2018-5455 is a critical authentication bypass vulnerability in Moxa OnCell G3100-HSPA Series, published on 5 Mar 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A Reliance on Cookies without Validation and Integrity Checking issue was discovered in Moxa OnCell G3100-HSPA Series version 1.4 Build 16062919 and prior. The application allows a cookie parameter to consist of only digits, allowing an attacker to perform a brute force attack bypassing authentication and gaining access to device functions.

Weakness: CWE-287 (Improper Authentication), CWE-565 (Reliance on Cookies without Validation and Integrity Checking)

## Which versions are affected by CVE-2018-5455?

It affects 4 products.


Products: Moxa Oncell G3110-Hspa-T Firmware, Moxa Oncell G3110-Hspa Firmware, Moxa Oncell G3150-Hspa-T Firmware, Moxa Oncell G3150-Hspa Firmware.

## How do I fix CVE-2018-5455?

No fix has been published for CVE-2018-5455 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-5455 being exploited?

There is no known exploitation of CVE-2018-5455 in the wild and no public exploit code.

## Other vulnerabilities in Moxa OnCell G3100-HSPA Series

- [CVE-2018-5453](https://insights.sbomify.com/CVE-2018-5453/): Denial of service in Moxa OnCell G3100-HSPA Series (high 7.5)
- [CVE-2018-5449](https://insights.sbomify.com/CVE-2018-5449/): Null dereference in Moxa OnCell G3100-HSPA Series (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-5455 and fix it if it is affected.

What it is: CVE-2018-5455 is a critical authentication bypass vulnerability in Moxa OnCell G3100-HSPA Series, published on 5 Mar 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2018-5455 in the wild and no public exploit code.

Affected product: Moxa OnCell G3100-HSPA Series. 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-2018-5455/ (Markdown: https://insights.sbomify.com/CVE-2018-5455/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-5455
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-5455
- OSV: https://osv.dev/vulnerability/CVE-2018-5455

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-5455/
Summaries are generated and may contain mistakes; the official description above is the record.