# CVE-2018-8304: Windows DNSAPI Denial of Service Vulnerability

CVE-2018-8304 is fixed in 28 products on 1 platform, first by KB4338814, released July 10, 2018. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2018-8304
- Priority: Routine
- CVSS: 5.9 (Important)
- EPSS: 0.1292
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Vendor exploitability assessment: N/A
- Published: Jul 19, 2018
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2018-8304

## Description

<p>A denial of service vulnerability exists in Windows <a href="https://technet.microsoft.com/en-us/library/security/dn848375.aspx#DNS">Domain Name System (DNS)</a> DNSAPI.dll when it fails to properly handle DNS responses. An attacker who successfully exploited the vulnerability could cause a system to stop responding. Note that the denial of service condition would not allow an attacker to execute code or to elevate user privileges. However, the denial of service condition could prevent authorized users from using system resources.</p> <p>To exploit the vulnerability, the attacker would use a malicious DNS server to send corrupted DNS responses to the target.</p> <p>The update addresses the vulnerability by modifying how Windows DNSAPI.dll handles DNS responses.</p>

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Microsoft | Windows 10 Version 1607 for 32-bit Systems | 14393.2368 | [KB4345418](https://patchblox.com/security/data/fix/microsoft/kb4345418.md) | Jul 16, 2018 |
| Microsoft | Windows 10 Version 1607 for 32-bit Systems | 14393.2363 | [KB4338814](https://patchblox.com/security/data/fix/microsoft/kb4338814.md) | Jul 10, 2018 |
| Microsoft | Windows 10 Version 1607 for x64-based Systems | 14393.2368 | [KB4345418](https://patchblox.com/security/data/fix/microsoft/kb4345418.md) | Jul 16, 2018 |
| Microsoft | Windows 10 Version 1607 for x64-based Systems | 14393.2363 | [KB4338814](https://patchblox.com/security/data/fix/microsoft/kb4338814.md) | Jul 10, 2018 |
| Microsoft | Windows 10 Version 1703 for 32-bit Systems | 15063.1209 | [KB4345419](https://patchblox.com/security/data/fix/microsoft/kb4345419.md) | Jul 16, 2018 |
| Microsoft | Windows 10 Version 1703 for 32-bit Systems | 15063.1206 | [KB4338826](https://patchblox.com/security/data/fix/microsoft/kb4338826.md) | Jul 10, 2018 |
| Microsoft | Windows 10 Version 1703 for x64-based Systems | 15063.1209 | [KB4345419](https://patchblox.com/security/data/fix/microsoft/kb4345419.md) | Jul 16, 2018 |
| Microsoft | Windows 10 Version 1703 for x64-based Systems | 15063.1206 | [KB4338826](https://patchblox.com/security/data/fix/microsoft/kb4338826.md) | Jul 10, 2018 |
| Microsoft | Windows 10 Version 1709 for 32-bit Systems | 16299.551 | [KB4345420](https://patchblox.com/security/data/fix/microsoft/kb4345420.md) | Jul 16, 2018 |
| Microsoft | Windows 10 Version 1709 for 32-bit Systems | 16299.547 | [KB4338825](https://patchblox.com/security/data/fix/microsoft/kb4338825.md) | Jul 10, 2018 |
| Microsoft | Windows 10 Version 1709 for x64-based Systems | 16299.551 | [KB4345420](https://patchblox.com/security/data/fix/microsoft/kb4345420.md) | Jul 16, 2018 |
| Microsoft | Windows 10 Version 1709 for x64-based Systems | 16299.547 | [KB4338825](https://patchblox.com/security/data/fix/microsoft/kb4338825.md) | Jul 10, 2018 |
| Microsoft | Windows 10 for 32-bit Systems | 10240.17918 | [KB4345455](https://patchblox.com/security/data/fix/microsoft/kb4345455.md) | Jul 16, 2018 |
| Microsoft | Windows 10 for 32-bit Systems | 10240.17914 | [KB4338829](https://patchblox.com/security/data/fix/microsoft/kb4338829.md) | Jul 10, 2018 |
| Microsoft | Windows 10 for x64-based Systems | 10240.17918 | [KB4345455](https://patchblox.com/security/data/fix/microsoft/kb4345455.md) | Jul 16, 2018 |
| Microsoft | Windows 10 for x64-based Systems | 10240.17914 | [KB4338829](https://patchblox.com/security/data/fix/microsoft/kb4338829.md) | Jul 10, 2018 |
| Microsoft | Windows 7 for 32-bit Systems Service Pack 1 |  | [KB4338823](https://patchblox.com/security/data/fix/microsoft/kb4338823.md) | Jul 19, 2018 |
| Microsoft | Windows 7 for 32-bit Systems Service Pack 1 |  | [KB4338818](https://patchblox.com/security/data/fix/microsoft/kb4338818.md) | Jul 10, 2018 |
| Microsoft | Windows 7 for 32-bit Systems Service Pack 1 |  | [KB4338821](https://patchblox.com/security/data/fix/microsoft/kb4338821.md) | Jul 10, 2018 |
| Microsoft | Windows 7 for 32-bit Systems Service Pack 1 |  | [KB4345459](https://patchblox.com/security/data/fix/microsoft/kb4345459.md) | Jul 10, 2018 |
| Microsoft | Windows 7 for x64-based Systems Service Pack 1 |  | [KB4338823](https://patchblox.com/security/data/fix/microsoft/kb4338823.md) | Jul 19, 2018 |
| Microsoft | Windows 7 for x64-based Systems Service Pack 1 |  | [KB4338818](https://patchblox.com/security/data/fix/microsoft/kb4338818.md) | Jul 10, 2018 |
| Microsoft | Windows 7 for x64-based Systems Service Pack 1 |  | [KB4338821](https://patchblox.com/security/data/fix/microsoft/kb4338821.md) | Jul 10, 2018 |
| Microsoft | Windows 7 for x64-based Systems Service Pack 1 |  | [KB4345459](https://patchblox.com/security/data/fix/microsoft/kb4345459.md) | Jul 10, 2018 |
| Microsoft | Windows 8.1 for 32-bit systems |  | [KB4338824](https://patchblox.com/security/data/fix/microsoft/kb4338824.md) | Jul 19, 2018 |
| Microsoft | Windows 8.1 for 32-bit systems |  | [KB4338815](https://patchblox.com/security/data/fix/microsoft/kb4338815.md) | Jul 10, 2018 |
| Microsoft | Windows 8.1 for 32-bit systems |  | [KB4338831](https://patchblox.com/security/data/fix/microsoft/kb4338831.md) | Jul 10, 2018 |
| Microsoft | Windows 8.1 for 32-bit systems |  | [KB4345424](https://patchblox.com/security/data/fix/microsoft/kb4345424.md) | Jul 10, 2018 |
| Microsoft | Windows 8.1 for x64-based systems |  | [KB4338824](https://patchblox.com/security/data/fix/microsoft/kb4338824.md) | Jul 19, 2018 |
| Microsoft | Windows 8.1 for x64-based systems |  | [KB4338815](https://patchblox.com/security/data/fix/microsoft/kb4338815.md) | Jul 10, 2018 |
| Microsoft | Windows 8.1 for x64-based systems |  | [KB4338831](https://patchblox.com/security/data/fix/microsoft/kb4338831.md) | Jul 10, 2018 |
| Microsoft | Windows 8.1 for x64-based systems |  | [KB4345424](https://patchblox.com/security/data/fix/microsoft/kb4345424.md) | Jul 10, 2018 |
| Microsoft | Windows RT 8.1 |  | [KB4338815](https://patchblox.com/security/data/fix/microsoft/kb4338815.md) | Jul 10, 2018 |
| Microsoft | Windows Server 2008 R2 for Itanium-Based Systems Service Pack 1 |  | [KB4338823](https://patchblox.com/security/data/fix/microsoft/kb4338823.md) | Jul 19, 2018 |
| Microsoft | Windows Server 2008 R2 for Itanium-Based Systems Service Pack 1 |  | [KB4338818](https://patchblox.com/security/data/fix/microsoft/kb4338818.md) | Jul 10, 2018 |
| Microsoft | Windows Server 2008 R2 for Itanium-Based Systems Service Pack 1 |  | [KB4338821](https://patchblox.com/security/data/fix/microsoft/kb4338821.md) | Jul 10, 2018 |
| Microsoft | Windows Server 2008 R2 for Itanium-Based Systems Service Pack 1 |  | [KB4345459](https://patchblox.com/security/data/fix/microsoft/kb4345459.md) | Jul 10, 2018 |
| Microsoft | Windows Server 2008 R2 for x64-based Systems Service Pack 1 |  | [KB4338823](https://patchblox.com/security/data/fix/microsoft/kb4338823.md) | Jul 19, 2018 |
| Microsoft | Windows Server 2008 R2 for x64-based Systems Service Pack 1 |  | [KB4338818](https://patchblox.com/security/data/fix/microsoft/kb4338818.md) | Jul 10, 2018 |
| Microsoft | Windows Server 2008 R2 for x64-based Systems Service Pack 1 |  | [KB4338821](https://patchblox.com/security/data/fix/microsoft/kb4338821.md) | Jul 10, 2018 |
| Microsoft | Windows Server 2008 R2 for x64-based Systems Service Pack 1 |  | [KB4345459](https://patchblox.com/security/data/fix/microsoft/kb4345459.md) | Jul 10, 2018 |
| Microsoft | Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation) |  | [KB4338823](https://patchblox.com/security/data/fix/microsoft/kb4338823.md) | Jul 19, 2018 |
| Microsoft | Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation) |  | [KB4338818](https://patchblox.com/security/data/fix/microsoft/kb4338818.md) | Jul 10, 2018 |
| Microsoft | Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation) |  | [KB4338821](https://patchblox.com/security/data/fix/microsoft/kb4338821.md) | Jul 10, 2018 |
| Microsoft | Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation) |  | [KB4345459](https://patchblox.com/security/data/fix/microsoft/kb4345459.md) | Jul 10, 2018 |
| Microsoft | Windows Server 2008 for 32-bit Systems Service Pack 2 |  | [KB4291391](https://patchblox.com/security/data/fix/microsoft/kb4291391.md) | Jul 19, 2018 |
| Microsoft | Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation) |  | [KB4291391](https://patchblox.com/security/data/fix/microsoft/kb4291391.md) | Jul 19, 2018 |
| Microsoft | Windows Server 2008 for Itanium-Based Systems Service Pack 2 |  | [KB4291391](https://patchblox.com/security/data/fix/microsoft/kb4291391.md) | Jul 19, 2018 |
| Microsoft | Windows Server 2008 for x64-based Systems Service Pack 2 |  | [KB4291391](https://patchblox.com/security/data/fix/microsoft/kb4291391.md) | Jul 19, 2018 |
| Microsoft | Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation) |  | [KB4291391](https://patchblox.com/security/data/fix/microsoft/kb4291391.md) | Jul 19, 2018 |
| Microsoft | Windows Server 2012 |  | [KB4338820](https://patchblox.com/security/data/fix/microsoft/kb4338820.md) | Jul 19, 2018 |
| Microsoft | Windows Server 2012 |  | [KB4338830](https://patchblox.com/security/data/fix/microsoft/kb4338830.md) | Jul 10, 2018 |
| Microsoft | Windows Server 2012 |  | [KB4338816](https://patchblox.com/security/data/fix/microsoft/kb4338816.md) | Jul 10, 2018 |
| Microsoft | Windows Server 2012 |  | [KB4345425](https://patchblox.com/security/data/fix/microsoft/kb4345425.md) | Jul 10, 2018 |
| Microsoft | Windows Server 2012 (Server Core installation) |  | [KB4338820](https://patchblox.com/security/data/fix/microsoft/kb4338820.md) | Jul 19, 2018 |
| Microsoft | Windows Server 2012 (Server Core installation) |  | [KB4338830](https://patchblox.com/security/data/fix/microsoft/kb4338830.md) | Jul 10, 2018 |
| Microsoft | Windows Server 2012 (Server Core installation) |  | [KB4338816](https://patchblox.com/security/data/fix/microsoft/kb4338816.md) | Jul 10, 2018 |
| Microsoft | Windows Server 2012 (Server Core installation) |  | [KB4345425](https://patchblox.com/security/data/fix/microsoft/kb4345425.md) | Jul 10, 2018 |
| Microsoft | Windows Server 2012 R2 |  | [KB4338824](https://patchblox.com/security/data/fix/microsoft/kb4338824.md) | Jul 19, 2018 |
| Microsoft | Windows Server 2012 R2 |  | [KB4338815](https://patchblox.com/security/data/fix/microsoft/kb4338815.md) | Jul 10, 2018 |
| Microsoft | Windows Server 2012 R2 |  | [KB4338831](https://patchblox.com/security/data/fix/microsoft/kb4338831.md) | Jul 10, 2018 |
| Microsoft | Windows Server 2012 R2 |  | [KB4345424](https://patchblox.com/security/data/fix/microsoft/kb4345424.md) | Jul 10, 2018 |
| Microsoft | Windows Server 2012 R2 (Server Core installation) |  | [KB4338824](https://patchblox.com/security/data/fix/microsoft/kb4338824.md) | Jul 19, 2018 |
| Microsoft | Windows Server 2012 R2 (Server Core installation) |  | [KB4338815](https://patchblox.com/security/data/fix/microsoft/kb4338815.md) | Jul 10, 2018 |
| Microsoft | Windows Server 2012 R2 (Server Core installation) |  | [KB4338831](https://patchblox.com/security/data/fix/microsoft/kb4338831.md) | Jul 10, 2018 |
| Microsoft | Windows Server 2012 R2 (Server Core installation) |  | [KB4345424](https://patchblox.com/security/data/fix/microsoft/kb4345424.md) | Jul 10, 2018 |
| Microsoft | Windows Server 2016 | 14393.2368 | [KB4345418](https://patchblox.com/security/data/fix/microsoft/kb4345418.md) | Jul 16, 2018 |
| Microsoft | Windows Server 2016 | 14393.2363 | [KB4338814](https://patchblox.com/security/data/fix/microsoft/kb4338814.md) | Jul 10, 2018 |
| Microsoft | Windows Server 2016 (Server Core installation) | 14393.2368 | [KB4345418](https://patchblox.com/security/data/fix/microsoft/kb4345418.md) | Jul 16, 2018 |
| Microsoft | Windows Server 2016 (Server Core installation) | 14393.2363 | [KB4338814](https://patchblox.com/security/data/fix/microsoft/kb4338814.md) | Jul 10, 2018 |
| Microsoft | Windows Server, version 1709  (Server Core Installation) | 16299.551 | [KB4345420](https://patchblox.com/security/data/fix/microsoft/kb4345420.md) | Jul 16, 2018 |
| Microsoft | Windows Server, version 1709  (Server Core Installation) | 16299.547 | [KB4338825](https://patchblox.com/security/data/fix/microsoft/kb4338825.md) | Jul 10, 2018 |

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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