2020-05-14

Security Flaws in Adobe Acrobat Reader Allow Malicious Program to Gain Root on macOS Silently

Yuebin Sun(@yuebinsun2020) of Tencent Security Xuanwu Lab

0x0 Summary

Today, Adobe Acrobat Reader DC for macOS patched three critical vulnerabilities(CVE-2020-9615, CVE-2020-9614, CVE-2020-9613) I reported. The only requirement needed to trigger the vulnerabilities is that Adobe Acrobat Reader DC has been installed. A normal user on macOS(with SIP enabled) can locally exploit this vulnerabilities chain to elevate privilege to the ROOT without a user being aware. In this blog, I will analyze the details of vulnerabilities and show how to exploit them.

0x1 Background

The root process has superpowers, it almost can do anything, reading/writing all sensitive files/databases such as Images/Calendars. However in modern macOS, root processes outside of sandbox are rare, most macOS built-in services run within a sandbox. They are no longer the king, they imprison themselves in a cage based on declarative sandbox profile rules.

Good news, popular software with high privileged services are new good target in addition to macOS built-in services, so Adobe Acrobat Reader DC catch my attention.

2020-02-26

macOS Security Framework and previous CVEs

Yuebin Sun(@yuebinsun2020) of Tencent Security Xuanwu Lab

Summary

COVID-19 outbreak keep me from going out，I have been researching macOS’s Security framework in the past two weeks of homeworking.

In this blog, I will try to analyze Security framework, especially Keychain, and previous vulnerabilities of the Secuirty framework。

Security Framework

Security framework is responsible for providing authentication and authorization, secure data storage and transportation, code signing, encryption/decryption services. Apps can use this services by using API of Security framework directly without knowing or caring about its implementation details.

But what are the components which composes the Security framework, and how the components collaborate with each other?

2020-02-26

macOS Security Framework and previous CVEs

Yuebin Sun(@yuebinsun2020) of Tencent Security Xuanwu Lab

摘要

新冠病毒疫情出不了门，在家办公这两周笔者研究了一下 macOS 的 Security Framework。

本文主要分析 Security Framework 尤其是其中 Keychain 的架构，将 Security Framework 近一两年的历史漏洞做个整理。

Security Framework 简介

Security Framework 主要负责为 App 提供认证与授权、安全数据存储与传输（Keychain，App Transport Security）、代码签名、加密解密功能。

第三方 App 通过引用 Security Framework，使用 Apple 提供的 API 就可以直接使用这些功能，不用关心底层实现的细节。

但 Security Framework 都有哪些组件，又是如何构建起来的呢？

2019-03-31

Microsoft Edge Chakra OP_NewScObjArray 类型混淆漏洞分析笔记

Yuebin Sun(@yuebinsun2020)

1 环境信息

Windows 10 X64 14393 (1607) - 没有安装过任何补丁
Microsoft Edge 38.14393.0.0
Microsoft EdgeHTML 14.14393

2 Crash Point

(1648.f78): Access violation - code c0000005 (first chance)
First chance exceptions are reported before any exception handling.
This exception may be expected and handled.
chakra!Js::DynamicProfileInfo::RecordCallSiteInfo+0x75:
00007ff9`dc43d0c5 66418500        test    word ptr [r8],ax ds:000001e5`b6a4f048=????
0:010> kb
 # RetAddr           : Args to Child                                                           : Call Site
00 00007ff9`dc23d3ea : 000001e5`b6950020 000001e5`d56f01a0 00000000`0000fefa 00007ff9`dc9583c8 : chakra!Js::DynamicProfileInfo::RecordCallSiteInfo+0x75
01 00007ff9`dc23def7 : 000001e5`b8ff97c0 0000004a`3a3fb100 000001e5`d0f407e0 00007ff9`dc37fefa : chakra!Js::ProfilingHelpers::ProfiledNewScObjArray+0x9e
02 00007ff9`dc38d74a : 0000004a`3a3fb410 000001e5`d6f3dc64 000001e5`b7bfa760 00007ff9`dc374943 : chakra!Js::InterpreterStackFrame::OP_NewScObjArray_Impl<Js::OpLayoutT_CallI<Js::LayoutSizePolicy<1> >,0>+0x8f
03 00007ff9`dc374cdd : 0000004a`3a3fb1e8 000001e5`d6f3dc63 000001e5`d6f3dc5f 00000000`00000000 : chakra!Js::JavascriptRegExpConstructor::GetPropertyBuiltIns+0xd22
04 00007ff9`dc374b07 : 0000004a`3a3fb410 00000000`00000000 00000000`00000001 00000000`00000000 : chakra!Js::InterpreterStackFrame::ProcessUnprofiled+0xbd
05 00007ff9`dc3736c9 : 0000004a`3a3fb410 0000004a`3a3fb410 0000004a`3a3fb410 00000000`00000001 : chakra!Js::InterpreterStackFrame::Process+0x1a7
06 00007ff9`dc375a04 : 0000004a`3a3fb410 000001e5`d6f3dc47 000001e5`d6f3dc47 00000000`00000000 : chakra!Js::InterpreterStackFrame::OP_TryCatch+0x61
07 00007ff9`dc374b07 : 0000004a`3a3fb410 00000000`00000000 00000000`00000000 00000000`00000000 : chakra!Js::InterpreterStackFrame::ProcessUnprofiled+0xde4
08 00007ff9`dc378b5e : 0000004a`3a3fb410 000001e5`d56f01a0 0000004a`3a3fbd80 00007ff9`e46a3f00 : chakra!Js::InterpreterStackFrame::Process+0x1a7
09 00007ff9`dc37a265 : 000001e5`d0f407e0 0000004a`3a3fbf50 000001e5`b65b0fba 0000004a`3a3fbf68 : chakra!Js::InterpreterStackFrame::InterpreterHelper+0x48e
0a 000001e5`b65b0fba : 0000004a`3a3fbfa0 00000000`00000001 0000004a`3a3fc378 00007ff9`dc4a0fe0 : chakra!Js::InterpreterStackFrame::InterpreterThunk+0x55
0b 00007ff9`dc4a1393 : 000001e5`d0f407e0 00000000`10000001 000001e5`ce93ff90 00000000`00000001 : 0x000001e5`b65b0fba
0c 00007ff9`dc36ef6d : 000001dd`a72844f0 00000000`00000008 000001e5`d0300110 0000004a`3a3fc001 : chakra!amd64_CallFunction+0x93
0d 00007ff9`dc372797 : 0000004a`3a3fc230 000001e5`d5874036 000001e5`d0f407e0 000001e5`00000001 : chakra!Js::InterpreterStackFrame::OP_CallCommon<Js::OpLayoutDynamicProfile<Js::OpLayoutT_CallIWithICIndex<Js::LayoutSizePolicy<0> > > >+0x15d
0e 00007ff9`dc376842 : 0000004a`3a3fc230 000001e5`d5874036 000001e5`00000119 00000000`00000000 : chakra!Js::InterpreterStackFrame::OP_ProfiledCallIWithICIndex<Js::OpLayoutT_CallIWithICIndex<Js::LayoutSizePolicy<0> > >+0xa7
0f 00007ff9`dc374aa2 : 0000004a`3a3fc230 00000000`00000000 00000000`00000000 00000000`00000000 : chakra!Js::InterpreterStackFrame::ProcessProfiled+0x132
10 00007ff9`dc378b5e : 0000004a`3a3fc230 000001e5`d56f0000 0000004a`3a3fc390 ffffffff`ffffff01 : chakra!Js::InterpreterStackFrame::Process+0x142
11 00007ff9`dc37a265 : 000001e5`d0f40900 0000004a`3a3fc560 000001e5`b65b0fc2 0000004a`3a3fc578 : chakra!Js::InterpreterStackFrame::InterpreterHelper+0x48e
12 000001e5`b65b0fc2 : 0000004a`3a3fc5b0 00000000`00000000 00000000`00000000 00007ff9`dc4a0fe0 : chakra!Js::InterpreterStackFrame::InterpreterThunk+0x55
13 00007ff9`dc4a1393 : 000001e5`d0f40900 00000000`00000000 00000000`00000000 00000000`00000000 : 0x000001e5`b65b0fc2
14 00007ff9`dc36d873 : 000001dd`a72844f0 00000000`00000000 000001e5`d0316f00 00007ff9`dc3d2f87 : chakra!amd64_CallFunction+0x93
15 00007ff9`dc3dc2ec : 000001e5`d0f40900 00007ff9`dc4a15a0 0000004a`3a3fc6c0 000001e5`d030e6d0 : chakra!Js::JavascriptFunction::CallFunction<1>+0x83
16 00007ff9`dc3db8b6 : 000001e5`d0f40900 0000004a`3a3fc7a0 000001e5`d030e6d0 0000004a`3a3fc700 : chakra!Js::JavascriptFunction::CallRootFunctionInternal+0x104
17 00007ff9`dc486259 : 000001e5`d0f40900 0000004a`3a3fc840 000001e5`d030e6d0 00000000`00000000 : chakra!Js::JavascriptFunction::CallRootFunction+0x4a
18 00007ff9`dc3e1d41 : 000001e5`d0f40900 0000004a`3a3fc8a0 00000000`00000000 0000004a`3a3fc880 : chakra!ScriptSite::CallRootFunction+0xb5
19 00007ff9`dc392a1d : 000001e5`d030cf00 000001e5`d0f40900 0000004a`3a3fc950 00000000`00000000 : chakra!ScriptSite::Execute+0x131
...

2017-07-23

GeekPwn 2016 Windows 服务提权漏洞的分析和利用

Yuebin Sun(@yuebinsun2020)

摘要

GeekPwn 2016 比赛中有一道 Windows 服务漏洞提权题目，该服务程序会创建命名管道（Named Pipe）服务端接收客户端发送的文件路径然后调用 LoadLibrary 加载，但加载之前有一系列的检查过程，我们的最终目标是绕过这些检查，加载我们指定的 DLL并以 SYSTEM 权限执行任意代码。本文笔者逐一分析该服务的各个验证环节及其绕过方法，以及如何组合他们最终启动 SYSTEM 权限的计算器。

服务端的处理逻辑:

服务端创建命名管道，等待客户端的连接。
客户端连接之后，服务端OpenProcess 打开客户端进程句柄，获得客户端进程 Image 文件路径。
验证客户端 Image 文件路径的签名。
签名验证通过之后，创建 Event 事件对象，无限等待 Event 对象直到 Signaled 状态。
通过管道接受客户端发送的 DLL 文件路径。
验证 DLL 文件路径的签名，签名通过之后调用 LoadLibrary 加载 DLL。

2017-05-30

Windows Logical EoP Workshop Writeup

Yuebin Sun(@yuebinsun2020)

这份文档是对 James Forshaw 2017 年公开的《Windows Logical EoP Workshop》逻辑漏洞本地提权 Workshop 的分析调试笔记。

1 环境搭建

1.1 虚拟机快照一次

如果方便，建议生成一次系统快照，方便实验结束之后恢复系统环境

1.2 关闭驱动签名验证，以便测试自己编写的驱动

只有关闭了这个签名验证的保护，Windows 系统才允许加载用户自己编写的驱动。另外，这个特性是针对 64 位 Windows 8/10 的，如果用的是 32 位系统，可以忽略。

管理员权限运行：

C:\Windows\system32>Bcdedit.exe -set TESTSIGNING ON
操作成功完成。

C:\Windows\system32>

2017-01-01

Hello Hexo

KNOCK KNOCK KNOCK