# CVE-2016-3321: Internet Explorer Information Disclosure Vulnerability

CVE-2016-3321 is fixed in 14 products on 1 platform, first by KB3176493, released August 9, 2016. It is not reported as exploited, but the vendor rates exploitation more likely. Patch Radar priority: Urgent.

- Web page: https://patchblox.com/security/cve/CVE-2016-3321
- Priority: Urgent
- CVSS: 2.6 (Moderate)
- EPSS: 0.3795
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Vendor exploitability assessment: Exploitation More Likely
- Published: Aug 9, 2016
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2016-3321

## Description

<p>An information disclosure vulnerability exists when Internet Explorer improperly handles page content, which could allow an attacker to detect the existence of specific files on the user's system.</p> <p>To exploit the vulnerability, in a web-based attack scenario, an attacker could host a website that is used to attempt to exploit the vulnerability. In addition, compromised websites and websites that accept or host user-provided content could contain specially crafted content that could exploit the vulnerability. In all cases, however, an attacker would have no way to force users to view the attacker-controlled content. Instead, an attacker would have to convince users to take action. For example, an attacker could trick users into clicking a link that takes them to the attacker's site.</p> <p>The security update addresses the vulnerability by helping to ensure that page content is properly validated in Internet Explorer.</p>

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Microsoft | Internet Explorer 10 on Windows Server 2012 |  | [KB3175443](https://patchblox.com/security/data/fix/microsoft/kb3175443.md) | Aug 9, 2016 |
| Microsoft | Internet Explorer 11 on Windows 10 Version 1511 for 32-bit Systems | 10586.545 | [KB3176493](https://patchblox.com/security/data/fix/microsoft/kb3176493.md) | Aug 9, 2016 |
| Microsoft | Internet Explorer 11 on Windows 10 Version 1511 for x64-based Systems | 10586.545 | [KB3176493](https://patchblox.com/security/data/fix/microsoft/kb3176493.md) | Aug 9, 2016 |
| Microsoft | Internet Explorer 11 on Windows 10 Version 1607 for 32-bit Systems | 14393.51 | [KB3176495](https://patchblox.com/security/data/fix/microsoft/kb3176495.md) | Aug 9, 2016 |
| Microsoft | Internet Explorer 11 on Windows 10 Version 1607 for x64-based Systems | 14393.51 | [KB3176495](https://patchblox.com/security/data/fix/microsoft/kb3176495.md) | Aug 9, 2016 |
| Microsoft | Internet Explorer 11 on Windows 10 for 32-bit Systems | 10240.17071 | [KB3176492](https://patchblox.com/security/data/fix/microsoft/kb3176492.md) | Aug 9, 2016 |
| Microsoft | Internet Explorer 11 on Windows 10 for x64-based Systems | 10240.17071 | [KB3176492](https://patchblox.com/security/data/fix/microsoft/kb3176492.md) | Aug 9, 2016 |
| Microsoft | Internet Explorer 11 on Windows 7 for 32-bit Systems Service Pack 1 |  | [KB3175443](https://patchblox.com/security/data/fix/microsoft/kb3175443.md) | Aug 9, 2016 |
| Microsoft | Internet Explorer 11 on Windows 7 for x64-based Systems Service Pack 1 |  | [KB3175443](https://patchblox.com/security/data/fix/microsoft/kb3175443.md) | Aug 9, 2016 |
| Microsoft | Internet Explorer 11 on Windows 8.1 for 32-bit systems |  | [KB3175443](https://patchblox.com/security/data/fix/microsoft/kb3175443.md) | Aug 9, 2016 |
| Microsoft | Internet Explorer 11 on Windows 8.1 for x64-based systems |  | [KB3175443](https://patchblox.com/security/data/fix/microsoft/kb3175443.md) | Aug 9, 2016 |
| Microsoft | Internet Explorer 11 on Windows RT 8.1 |  | [KB3175443](https://patchblox.com/security/data/fix/microsoft/kb3175443.md) | Aug 9, 2016 |
| Microsoft | Internet Explorer 11 on Windows Server 2008 R2 for x64-based Systems Service Pack 1 |  | [KB3175443](https://patchblox.com/security/data/fix/microsoft/kb3175443.md) | Aug 9, 2016 |
| Microsoft | Internet Explorer 11 on Windows Server 2012 R2 |  | [KB3175443](https://patchblox.com/security/data/fix/microsoft/kb3175443.md) | Aug 9, 2016 |

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Data as of 2026-11-07T12:40:37Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo