关联漏洞
标题:Microsoft Windows DNS Server 输入验证错误漏洞 (CVE-2020-1350)Description:Microsoft Windows是美国微软（Microsoft）公司的一套个人设备使用的操作系统。 Microsoft Windows DNS Server 存在输入验证错误漏洞，该漏洞源于程序无法正确处理请求。攻击者可通过发送恶意的请求利用该漏洞在本地系统帐户的上下文中运行任意代码。以下产品及版本受到影响：Windows Server 2008 SP2，Windows Server 2008 R2 SP1，Windows Server 2012，Windows Server 2012 R2，Windo
Description
A registry-based workaround can be used to help protect an affected Windows server, and it can be implemented without requiring an administrator to restart the server. Because of the volatility of this vulnerability, administrators may have to implement the workaround before they apply the security update in order to enable them to update their systems by using a standard deployment cadence.
介绍
# [KB4569509: Guidance for DNS Server Vulnerability CVE-2020-1350](https://support.microsoft.com/en-us/help/4569509/windows-dns-server-remote-code-execution-vulnerability)
## Introduction
On July 14, 2020, Microsoft released a security update for the issue that is described in CVE-2020-1350 | Windows DNS Server Remote Code Execution Vulnerability. This advisory describes a Critical Remote Code Execution (RCE) vulnerability that affects Windows servers that are configured to run the DNS Server role. We strongly recommend that server administrators apply the security update at their earliest convenience.
A registry-based workaround can be used to help protect an affected Windows server, and it can be implemented without requiring an administrator to restart the server. Because of the volatility of this vulnerability, administrators may have to implement the workaround before they apply the security update in order to enable them to update their systems by using a standard deployment cadence.
## Workaround
**Optional:** Download the workaround script from the [GitHub Repository](https://github.com/simeononsecurity/CVE-2020-1350-Fix)
To work around this vulnerability, make the following registry change to restrict the size of the largest inbound TCP-based DNS response packet that's allowed:
Subkey: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\DNS\Parameters
Value: TcpReceivePacketSize
Type: DWORD
Value data: 0xFF00
**Notes:**
The default (also maximum) Value data = 0xFFFF.
The recommended Value data = 0xFF00 (255 bytes less than the maximum).
You must restart the DNS Service for the registry change to take effect. To do this, run the following command at an elevated command prompt:
```net stop dns && net start dns```
##Important information about this workaround
TCP-based DNS response packets that exceed the recommended value will be dropped without error. Therefore, it is possible that some queries might not be answered. This could cause an unanticipated failure. A DNS server will be negatively impacted by this workaround only if it receives valid TCP responses that are greater than allowed in the previous mitigation (more than 65,280 bytes).
The reduced value is unlikely to affect standard deployments or recursive queries. However, a non-standard use-case may exist in a given environment. To determine whether the server implementation will be adversely affected by this workaround, you should enable diagnostic logging, and capture a sample set that is representative of your typical business flow. Then, you will have to review the log files to identify the presence of anomalously large TCP response packets
For more information, see [DNS Logging and Diagnostics](https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2012-r2-and-2012/dn800669%28v=ws.11%29).
文件快照
[4.0K] /data/pocs/f67f6a2a062be90704a1686487949b8b9319aad8
├── [ 131] CVE-2020-1350_DNS_Server_Vulnerability.ps1
└── [2.8K] README.md
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