# CVE-2016-3321: Information disclosure in n/a

> Local attackers can enumerate files on the system by exploiting file existence checks in Internet Explorer via HTML5 sandbox iframes.

- **Severity:** Low 2.5 (`CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N`)
- **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:** 9 Aug 2016
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-q89r-f728-w9pv

## What is CVE-2016-3321?

CVE-2016-3321 is a low-severity vulnerability in Microsoft Internet Explorer, published on 9 Aug 2016. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Microsoft Internet Explorer 10 and 11 load different files for attempts to open a file:// URL depending on whether the file exists, which allows local users to enumerate files via vectors involving a file:// URL and an HTML5 sandbox iframe, aka "Internet Explorer Information Disclosure Vulnerability."

Weakness: CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2016-3321?

It affects 1 product.


Products: Microsoft Internet Explorer.

## How do I fix CVE-2016-3321?

No fix has been published for CVE-2016-3321 yet. Limit exposure of the affected software until one is available.

## Is CVE-2016-3321 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2016-3321 exists.

Public exploit code:

- Internet Explorer Iframe Sandbox File Name Disclosure Vulnerability (metasploit)

## Other vulnerabilities in Microsoft Internet Explorer

- [CVE-2014-1776](https://insights.sbomify.com/CVE-2014-1776/): Microsoft Internet Explorer Memory Corruption (critical 9.8, exploited in the wild)
- [CVE-2021-27085](https://insights.sbomify.com/CVE-2021-27085/): Microsoft Internet Explorer Remote Code Execution (high 8.8, exploited in the wild)
- [CVE-2017-0222](https://insights.sbomify.com/CVE-2017-0222/): Microsoft Internet Explorer Remote Code Execution (high 8.8, exploited in the wild)
- [CVE-2017-0210](https://insights.sbomify.com/CVE-2017-0210/): Microsoft Internet Explorer Privilege Escalation (high 8.8, exploited in the wild)
- [CVE-2017-0149](https://insights.sbomify.com/CVE-2017-0149/): Microsoft Internet Explorer Memory Corruption (high 8.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2016-3321 and fix it if it is affected.

What it is: CVE-2016-3321 is a low-severity vulnerability in Microsoft Internet Explorer, published on 9 Aug 2016. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2016-3321 exists.

Affected product: Microsoft Internet Explorer. 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-2016-3321/ (Markdown: https://insights.sbomify.com/CVE-2016-3321/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2016-3321
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-3321
- OSV: https://osv.dev/vulnerability/CVE-2016-3321

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From sbomify Insights: https://insights.sbomify.com/CVE-2016-3321/
Summaries are generated and may contain mistakes; the official description above is the record.