rbndr - Simple DNS Rebinding Service

项目说明

rbndr

rbndr is a very simple, non-conforming, name server for testing software against DNS rebinding . The ser to queries by randomly selecting one of the addresses specified in the hostname and returning it as the answer with a very low ttl.

DNS rebinding is a form of TOCTOU (time of check, time of use) . You would use it if you have a service that uses "preflight" checks incorrectly to modify security properties. For example, consider a (fictional) browser plugin that has an api like this:

And AllowUntrustedAccess() simply sends a preflight HTTP request to the host:

If the service returns 200, then the plugin allows the hostpage complete access to that hostname. This might be a security , because you can specify a rbndr hostname that will switch between a host you control and a host you don't. The plugin might allow complete access to an arbitrary ip address (e.g. an internal service, or localhost) even if that service would not normally permit the preflight check.

This might sound unrealistic, but that's exactly how Adobe Flash, Oracle Java and lots of other products worked in the past, and many other products still work.

Read about how Adobe tried to resolve this problem in Flash here,

For software that is to this class of attack, rbndr is an easy way to test without having to modify /etc/hosts or setup your own nameserver. If the software associates the result with just the *hostname* and not the hostname and ip address, then you can grant yourself access to any ip address.

The format for hostnames is simply

But you can use this website to convert from dotted quads if you prefer:

For example, to switch between 127.0.0.1 and 192.168.0.1 you would encode them as dwords, and then use:

Let's test it out:

As you can see, the ser returns one of the addresses. You might do something like this (in pseudo-code):

项目信息

开发语言：C

Star 数：761

技术要点

该项目属于漏洞知识库方向的开源资源，代码结构清晰，适合安全研究人员学习参考。项目围绕Simple DNS Rebinding Service展开，提供了可运行的实现，对理解相关安全机制、工具原理与攻防技术具有较高的研究价值。

从技术实现角度看，此类项目的核心在于对底层原理的深入理解与工程化落地。开发者在研究过程中可以结合官方文档与社区讨论，梳理项目的初始化流程、核心模块职责与数据流转，逐步掌握其中的技术细节与设计思路。

使用与学习建议

1. 下载源码压缩包，解压到本地环境。

2. 根据项目类型准备对应的运行环境与依赖。

3. 按照 README 中的步骤完成配置与部署。

4. 在隔离的测试环境中运行验证，避免影响生产系统。

免责声明

本资源来源于开源社区，仅供安全研究、技术学习与合法授权范围内的攻防演练使用，请勿用于任何非法或侵害他人权益的用途。使用本项目产生的一切后果由使用者自行承担。