iOS Kernel Heap Armageddon - Hakim

More documents

Recommendations

Info

iOS Kernel Zone Allocator 101 • in case of a buffer overflow the freelist pointer is overwritten • next allocation will make attacker controlled pointer the head of freelist • and the allocation following after will return the injected pointer adjacent memory blocks head of freelist allocated block overflowing into free one attacker data head of freelist Stefan Esser • iOS Kernel Heap Armageddon REVISITED • July 2012 • 14
Exploiting the freelist in iOS 6 • Apple has changed the freelist handling in iOS 6 • memory is now tagged with a fixed value • doesn‘t stop freelist exploitation • but stops exploitation method used in all public iOS heap exploits Stefan Esser • iOS Kernel Heap Armageddon REVISITED • July 2012 • 15
Page 1 and 2: http://www.sektioneins.de iOS Kerne
Page 3 and 4: DISCLAIMER iOS 6 • is in beta =>
Page 5 and 6: So what is this talk about? • zon
Page 7 and 8: Some Kernel Zones $ zprint kalloc e
Page 9 and 10: iOS Kernel Zone Allocator 101 • k
Page 11 and 12: iOS Kernel Zone Allocator 101 • z
Page 13: iOS Kernel Zone Allocator 101 • w
Page 17 and 18: Overview Managers and Wrappers not
Page 19 and 20: kalloc() • kalloc() is a wrapper
Page 21 and 22: kfree() • kfree() is a bit specia
Page 23 and 24: _MALLOC() • _MALLOC() is a wrappe
Page 25 and 26: _MALLOC() in iOS 5.x void *_MALLOC(
Page 27 and 28: What about kern_os_malloc(), new an
Page 29 and 30: mcache / slab could and might fill
Page 31 and 32: kernel_memory_allocate • “maste
Page 33 and 34: Cross Zone Attacks • what is the
Page 35 and 36: Visualization of Zone Page Allocati
Page 61 and 62: Zone Page Allocation Distribution (
Page 63 and 64: Cross Memory Allocator Attacks •
Page 65 and 66:
iOS Kernel C++ • iOS kernel‘s l
Page 67 and 68:
OSObject Memory Layout 0x00 0x04 vt
Page 69 and 70:
Overwriting an OSObject in Memory
Page 71 and 72:
OSArray Memory Layout and Overwriti
Page 73 and 74:
“Generic“ Technique to control
Page 75 and 76:
Heap Feng Shui / Heap Massage / ...
Page 77 and 78:
OSUnserializeXML() • deserializat
Page 79 and 80:
How does the parser work? (II) •
Page 81 and 82:
How does the parser work? (IV) •
Page 83 and 84:
How does the parser work? (VI) •
Page 85 and 86:
How does the parser work? (VIII)
Page 87 and 88:
Heap Spraying (Remember?) • alloc
Page 89 and 90:
Heap Spraying • allocate repeated
Page 91 and 92:
Heap Spraying • allocate repeated
Page 93 and 94:
Fill Arbitrary Sized Memory Blocks
Page 95 and 96:
Poking Holes into Allocated Data
Page 97 and 98:
Extra: Keeping Data Allocated • s
show all

iOS Kernel Heap Armageddon - Hakim

Create successful ePaper yourself

Delete template?

Save as template?