Author Archives: flanker017

A theme pack to system privilege

Update: Huawei has assigned CVE-2017-2692, CVE-2017-2693

(中文版见 https://blog.flanker017.me/a-theme-to-system-in-emui/)

Download this theme pack, pwned with system shell?

Android users may be familiar with theme packs, which is a major advantage for Android over iOS. Two years ago we conducted a cooperation project with Huawei for digging vulnerabilities in Huawei’s EMUI3.1 and 4.0, with some vulnerabilities discovered, which of course had already been reported during the cooperation project and fixed.

Some of these bugs are quite interesting though, so I’d like to share it in a series of blogs. This blog will cover a vulnerability which can be initiated from both local and remote to get system privilege via malicious theme packs. If you download and install such a specially-crafted malicious theme from a third party channel, you will get pwned.

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A theme to system in EMUI

装了这个主题包,就被拿system shell?

各位Android用户一定对主题包不陌生,这应该是Android相对于iOS可定制化的一大优势。 说到主题包,各位会想到什么?这个?

哦不对,跑题了。那这个?

好了又跑题了,下面是正文。两年前,我们对EMUI3.1&4.0做了一次漏洞挖掘合作项目,发现了一些问题,都已通过该合作项目报给了华为并得到了修复。 其中有些漏洞的挖掘和利用过程还是很有意思的,在这里总结成系列文章分享给大家。下面介绍的是一个通过下载安装恶意主题远程和本地均可以发起攻击拿到system权限的漏洞。在第三方渠道下载安装了这样一个特定构造的主题,手机就会被拿到system权限。

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Racing for everyone: descriptor describes TOCTOU,苹果iOS/OSX内核中的新型漏洞

Racing for everyone: descriptor describes TOCTOU,苹果iOS/OSX内核中的新型漏洞

这篇文章是关于我们在苹果内核IOKit驱动中找到的一类新攻击面。之前写了个IDA脚本做了个简单扫描,发现了至少四个驱动都存在这类问题并报告给了苹果,苹果分配了3个CVE(CVE-2016-7620/4/5), 见 https://support.apple.com/kb/HT207423。 后来我和苹果的安全工程师聊天,他们告诉我他们根据这个pattern修复了十多个漏洞,包括iOS内核中多个可以利用的漏洞。

为了能更清楚地描述这类新漏洞,我们先来复习下IOKit的基础知识。

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Racing for everyone: descriptor describes TOCTOU in Apple's core

Racing for everyone: descriptor describes TOCTOU in Apple’s core

This blog post is about a new type of vulnerabilities in IOKit I discovered and submitted to Apple in 2016. I did a brief scan using a IDA script on MacOS and found at least four bugs with 3 CVEs assigned (CVE-2016-7620/4/5), see https://support.apple.com/kb/HT207423. I was told afterwards that there’re even more issues of this type on iOS’/OSX’s IOKit drivers and fortunately Apple fixed them also.

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Some examples of kernel infoleak bugs on Android

Recently as KASLR is slowly adopted into Android and because of the requirements of exploitation stability of previous bugs, kernel infoleak bugs are becoming more and more important. Here I want to explain two infoleak bugs on Android, one found by me and is fixed now, and other one is a known and fixed bug but very useful as it exists on all android platforms.

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一个矩形pwn掉整个内核系列之一 – zone的舞蹈

一个矩形pwn掉整个内核系列之一 – zone的舞蹈

一个矩形pwn掉整个内核?这听起来很马德里不思议,然而这真实地发生在了今年3月份温哥华的Pwn2Own赛场。这一系列文章会向大家分享我们这次沙箱逃逸用到的Blitzard CVE-2016-1815的发现和利用经历。我们通过三步走最终完成了这个利用,本文将先问大家介绍第二和第三步 – kalloc.48的舞蹈kalloc.8192 重剑无锋,在最后一篇文章中,我们会回到本源,介绍这个漏洞的起因。

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The Journey of a complete OSX privilege escalation with a single vulnerability – Part 1

The Journey of a complete OSX privilege escalation with a single vulnerability – Part 1

In previous blog posts Liang talked about the userspace privilege escalation vulnerability we found in WindowServer. Now in following articles I will talk about the Blitzard kernel bug we used in this year’s pwn2own to escape the Safari renderer sandbox, existing in the blit operation of graphics pipeline. From a exploiter’s prospective we took advantage of an vector out-of-bound access which under carefully prepared memory situations will lead to write-anywhere-but-value-restricted to achieve both infoleak and RIP control. In this article we will introduce the exploitation methods we played with mainly in kalloc.48 and kalloc.4096.

First we will first introduce the very function which the overflow occurs, what we can control and how these affect our following exploitation.

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Integer overflow due to compile behavior in OSX Kernel IOUSBHIDDevice

Interesting Integer overflow in enum comparison IOHIDDevice::handleReportWithTime

By flanker from KeenLab.

There exists a signed integer comparison overflow in IOHIDDevice::_getReport and then handleReportWithTime, which can lead to oob access/execute in handleReportWithTime. A normal process can leverage this vulnerability to archive potential code execution in kernel and escalate privilege.

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