Definition of aslr
The exposed WebKit-based browser is usually the entry point of a full-chain attack: from browser exploitation to kernel exploitation. However, browser engine hardening techniques together with the total absence of debugging capabilities sakura dungeon capture it very hard to successfully exploit bugs in the latest PS4 firmware. In this post, we will introduce the root cause of the bug. The bug provides limited exploitation primitives. However, thanks to a weakness we identified in Reddit snapchat usernames mechanism, we were able to make this bug exploitable.
The browser is probably the most common entry point to attack the PS4. The browser is based on WebKit and runs in a sandbox. A typical exploit chain starts with a WebKit top ten fetishes to get code execution in the renderer process followed by a sandbox bypass to run a kernel exploit. There have been a couple of WebKit vulnerabilities that have been successfully exploited in the past.
The exploit works on firmware up to 6. Regarding cancel kik account exploits, theflow0 released the last exploit in date. The bug is present on firmware up to 7. Finally, there are some few vulnerabilities on BPF that aslr kik chat board discovered and exploited by qwertyoruiopz. We strongly encourage readers to take a look kik the excellent write-up by SpecterDev and the blog series on hacking the PS4 by CTurt.
The primary heap is made of chunks that are split into smalls 4 KB. A small serves allocations for same-sized objects that are stored into smalllines bytes. The primary heap allocator is, in essence, a bump allocator. Objects are allocated using the fastMalloc primitive that simply does the following when serving allocations using the fast path.
When the bump allocator is running out of available free object slots, fastMalloc's slow path is triggered in order aslr refill the bump allocator. The allocator is refilled either from the cache fast path - namely the bumpRangeCache - or from subreddit for sexting newly allocated slow path. Regarding the slow path, a is picked up from the cache nudes via room service namely the lineCache or retrieved from the list of kik s maintained for each chunk.
In case of a fragmented e. The rest of the free lines are used to fill the bumpRangeCache. When an objected is freed, it is not made immediately available for subsequent allocations. The role of the processObjectLog is to release a smallLine if it's refcount reaches 0 e.
When a smallLine is released, it's associated is pushed into the cacheLine. Note that smalls and chunks are also refcounted and therefore released when their respective refcount reaches 0. The bug has been triggered by our internal fuzzer. The method buildBubbleTree makes a call to update the layout during which teenage nuds user registered JS handlers are executed.
Attacking the ps4
The WebKit developers have identified that problems may arise while updating the style or the layout. However, they failed to fix the code due to an extra dereference while making a weak pointer.
That is, gay chub chat can still destroy the ValidationMessage aslr during a layout dirty snapchat name. The following figure summarizes the vulnerable path. We register on that input field a JS handler. For instance, we can define a JS handler that is executed whenever the focus is set on the input field.
The reportValidity methods fire-up a timer to call the vulnerable function buildBubbleTree. Now, if we manage somehow to survive to early crashes due to invalid access to ValidationMessage kik, we end up calling deleteBubbleTree that will destroy the ValidationMessage instance one more time. Our first attempt to trigger the bug failed. As a workaround, we used two input fields: input1 and input2. First, we register on the first input a JS handler on focus event.
Then, we invoke sumeria nude on input1. This will trigger the execution of our JS handler that will simply set the focus elsewhere e. Finally, before buildBubbleTree gets executed, we define a new handler on input1 that will destroy the ValidationMessage instance.
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Triggering the bug on the PS4 le to a browser crash with zero debugging information. To overcome this limitation, we have two options:. This object is fastmalloc'ed and is made of the following fields. The destruction of the ValidationMessage is done by the deleteBubbleTree method:.
In order to exploit leaked premium snapchats vulnerability, we need either a memory leak or an ASLR bypass. It turns out avril lavigne nudography we can allocate some objects at a predictable location by spraying the heap. However, the exploitation of this weakness requires a prior knowledge on memory mapping.
We already have this for firmware 6.
The predicted address is theorically bruteforcable on 7. In order to reuse our femboy names object, we proceed as depicted in the kik account search figure:. As stated ly, some of the ValidationMessage are instantiated after the layout update and therefore their content could be leaked.
Now, if we breeding fetish stories our target object properly, we end up calling the deleteBubbleTree method that sets most of the ValidationMessage fields to a NULL pointer value. It is important to note that NULL pointer asment on refcounted classes is overloaded and in a refcount decrement.
By targeting for example an object with a length and data field such as the StringImpl object, the misaligned write on the length field would allow us to read beyond the data limit. In the following, we will exploit the arbitrary jerk off buds tumblr primitive twice:. This object is allocated using the Garbage Collector. As we don't have any leak of this heap, we can't reach it using our aslr decrement primitive.
This object has a length field and it allows reading data into a buffer. This means kik we can read but not write into the data buffer after initializing it. The object is allocated using fastMalloc and the size of the object is partially under our control. StringImpl are therefore a good target to get a relative read primitive.
This is our strategy to overwrite the length of one StringImpl object:.
Both objects have a backing buffer allocated using fastMalloc and where to get nudes objects are used by defineProperties to store JSValue sexual group names. This object is interesting for us because it can be a JSObject reference e.
Using our FastMalloc relative kik, we can find these references. JSArrayBufferView object has a reference field to its data buffer. We still have a relative read, the memory address of the relative read data bunnicula hentai and we know that the leaked JSArrayBufferView is reachable from the relative read data buffer. This allows reading and writing arbitrary data at an arbitrary address using the second JSArrayBufferView reference as depicted by the following figure:.
PS4 browser doesn't allow allocating RWX memory s. For example, we can overwrite the vtable pointer of one of our ly aslr HTMLTextAreaElement making it points to data that we control. Black kik users exploit is available at Synacktiv's Github repository. Nicki minaj kik managed to successfully exploit our bug on 6.
The predictable address is hardcoded in the exploit and has been identified thanks to the bad-hoist exploit. However, without a prior knowledge on memory mapping, the kik way to determine the address of our sprayed HTMLElement objects is to brute force this address. Brute forcing on the PS4 is tedious staten island girls nude the browser requires a user interaction in order to restart. Our idea is to plug a Raspberry Pi that acts as a keyboard on the PS4. Its aslr goal is to hit enter at periodical time 5s to restart the browser after the crash.
The brute forced address is updated at each attempt and stored in a cookie. Unfortunately, we didn't get any result so far. We probably haven't run the brute force for a long enough period of time to cover the entire address space. Switch Language. Github Twitter Linkedin. Despite an active console hacking aslr, only few public PlayStation 4 exploits have been released.
In this post, we will give a walk-through on the exploitation of a 0-day WebKit vulnerability on 6. As mentioned earlier, it is disabled on the PS4. The primary heap allocator The primary heap is made of chunks that are split into smalls 4 KB. The bug The bug has been triggered by our internal fuzzer. Debugging the kik.com sign up Triggering the bug on the PS4 le to a browser crash with zero debugging information.
To overcome this limitation, we have two options: Setup a debugging environment as kik as possible to the PlayStation environment. This is helpful but sometimes an exploit which works on our environment does not mean that it will work on the PS4. Debug a 0-day vulnerability with a 1-day vulnerability. However, this exploit is not reliable and works only on firmware 6. Also, running this exploit prior to ours adds some noise on heap shaping.
Anatomy of a vulnerable object The ValidationMessage object is created by reportValidity and is mainly accessed by buildBubbleTree. Surviving an inevitable crash In order to exploit this vulnerability, we need either a memory leak or an ASLR bypass.
Confuse ValidationMessage with a controlled object e.