# CVE-2018-25221: EChat Server 3.1 Buffer Overflow via chat.ghp username Parameter

> Remote attackers can execute arbitrary code on EChat Server by sending a crafted GET request with an oversized username parameter to the chat.ghp endpoint.

- **Severity:** Critical 9.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 28 Mar 2026
- **Updated:** 1 Oct 2026
- **Also known as:** GHSA-4xgm-gv32-5pqv

## What is CVE-2018-25221?

CVE-2018-25221 is a critical memory corruption vulnerability in Echatserver EChat Server, published on 28 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

EChat Server 3.1 contains a buffer overflow vulnerability in the chat.ghp endpoint that allows remote attackers to execute arbitrary code by supplying an oversized username parameter. Attackers can send a GET request to chat.ghp with a malicious username value containing shellcode and ROP gadgets to achieve code execution in the application context.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2018-25221?

It affects 1 product.


Products: Echatserver Easy Chat Server.

## How do I fix CVE-2018-25221?

No fix has been published for CVE-2018-25221 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-25221 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2018-25221 exists.

## Other vulnerabilities in Echatserver EChat Server

- [CVE-2017-9544](https://insights.sbomify.com/CVE-2017-9544/): Memory corruption in n/a (critical 9.8)
- [CVE-2019-25613](https://insights.sbomify.com/CVE-2019-25613/): Easy Chat Server 3.1 Denial of Service via message Parameter (high 8.7)
- [CVE-2022-44939](https://insights.sbomify.com/CVE-2022-44939/): Other in n/a (high 7.8)
- [CVE-2019-20502](https://insights.sbomify.com/CVE-2019-20502/): Memory corruption in n/a (high 7.5)
- [CVE-2017-9543](https://insights.sbomify.com/CVE-2017-9543/): Auth bypass in n/a (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-25221 and fix it if it is affected.

What it is: CVE-2018-25221 is a critical memory corruption vulnerability in Echatserver EChat Server, published on 28 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2018-25221 exists.

Affected product: Echatserver EChat Server. 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-2018-25221/ (Markdown: https://insights.sbomify.com/CVE-2018-25221/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-25221
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-25221
- OSV: https://osv.dev/vulnerability/CVE-2018-25221

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-25221/
Summaries are generated and may contain mistakes; the official description above is the record.