Symbolic Link Vulnerability

By restoring files, directories and symlinks to the iOS device, the path is carefully checked, so that no write accesses outside of certain domains are possible. By creating a symlink that points to somewhere else, it is possible to overcome this limitation.

This vulnerability has been fixed in iOS 7.1b2.

Usage in evasi0n jailbreak[edit source]

In the case of evasi0n, the following files, directories and symlinks are restored, all in the Media Domain:

directory: Media/
directory: Media/Recordings/
symlink: Media/Recordings/.haxx pointing to /var/mobile
directory: Media/Recordings/.haxx/DemoApp.app/
several files in Media/Recordings/.haxx/DemoApp.app/, Info.plist, DemoApp, Icon.png, Icon@2x.png, Icon-72.png, Icon-72@2x.png
file: Media/Recordings/.haxx/Library/Caches/com.apple.mobile.installation.plist

This results in the following directory and file structure:

/var/mobile/Media/Recordings/ (folder)
/var/mobile/Media/Recordings/.haxx (symlink)

/var/mobile/DemoApp.app/Info.plist
/var/mobile/DemoApp.app/DemoApp
/var/mobile/DemoApp.app/Icon.png
/var/mobile/DemoApp.app/Icon@2x.png
/var/mobile/DemoApp.app/Icon-72.png
/var/mobile/DemoApp.app/Icon-72@2x.png

/var/mobile/Library/Caches/com.apple.mobile.installation.plist

References[edit source]

Accuvant Labs analysis of evasi0n Archived 2013-12-27 at the Wayback Machine

v t e Exploits
Exploits	0x24000 Segment Overflow ARM Exception Vector Info Leak ARM7 Go alloc8 Exploit amfid Lazy Binding Exploit amfid Text Relocation Exploit BPF_STX Kernel Write Exploit blackbird Exploit CVE-2013-0964 CVE-2021-30773 CVE-2021-30807 CVE-2021-30883 checkm8 Exploit CoreTrust Root Certificate Validation Vulnerability De Rebus Antiquis diags (iBoot command) Dual Boot Exploit Dynamic memmove() locating HFS Heap Overflow HFS Legacy Volume Name Stack Buffer Overflow iOS 5 HFS Heap Buffer Overflow IOSurface Kernel Exploit IOUSBDeviceFamily Vulnerability Incomplete Codesign Exploit Kernel memory write via ROP gadget libTiff Exploit limera1n Exploit Malformed CFF Vulnerability Malformed PairRequest MobileBackup Copy Exploit Overlapping Segment Attack posix_spawn kernel information leak Psychic Paper Pwnage Pwnage 2.0 Racoon String Format Overflow Exploit Ramdisk Hack SHA-1 Image Segment Overflow Shebang Trick Symbolic Link Vulnerability T1 Font Integer Overflow Timezone Vulnerability usb_control_msg(0x21, 2) Exploit usb_control_msg(0xA1, 1) Exploit v0rtex vm_map_copy_t corruption for arbitrary memory disclosure
Patches	/private/etc/fstab AMFI Binary Trust Cache Patch ASR Crazeles hgsp4 patch Hunnypot Kernel Patches PE_i_can_has_debugger Patch Sandbox Patch Signature Check Patch vm_map_enter Patch vm_map_protect Patch

Usage in evasi0n jailbreak[edit source]

See Also[edit source]

References[edit source]