# CVE-2016-9499: The Accellion FTP server prior to version FTA_9_12_220 is vulnerable to cross-site scripting.

> An attacker can enumerate valid user accounts by observing server responses to invalid username attempts, facilitating targeted attacks.

- **Severity:** Medium 5.3 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 13 Jul 2018
- **Updated:** 6 Aug 2024
- **Also known as:** GHSA-64mw-c7hp-gmxw

## What is CVE-2016-9499?

CVE-2016-9499 is a medium-severity vulnerability in Accellion FTP Server, published on 13 Jul 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Accellion FTP server prior to version FTA_9_12_220 only returns the username in the server response if the username is invalid. An attacker may use this information to determine valid user accounts and enumerate them.

Weakness: CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor), CWE-204 (Observable Response Discrepancy)

## Which versions are affected by CVE-2016-9499?

It affects 1 product.


Products: Accellion Ftp Server.

## How do I fix CVE-2016-9499?

No fix has been published for CVE-2016-9499 yet. Limit exposure of the affected software until one is available.

## Is CVE-2016-9499 being exploited?

There is no known exploitation of CVE-2016-9499 in the wild and no public exploit code.

## Other vulnerabilities in Accellion FTP Server

- [CVE-2016-9500](https://insights.sbomify.com/CVE-2016-9500/): The Accellion FTP server prior to version FTA_9_12_220 is vulnerable to informaiton exposure (medium 6.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2016-9499 and fix it if it is affected.

What it is: CVE-2016-9499 is a medium-severity vulnerability in Accellion FTP Server, published on 13 Jul 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-2016-9499 in the wild and no public exploit code.

Affected product: Accellion FTP 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-2016-9499/ (Markdown: https://insights.sbomify.com/CVE-2016-9499/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2016-9499
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-9499
- OSV: https://osv.dev/vulnerability/CVE-2016-9499

---
From sbomify Insights: https://insights.sbomify.com/CVE-2016-9499/
Summaries are generated and may contain mistakes; the official description above is the record.