macOS XNU - Copy-on-Write Behaviour Bypass via Partial-Page Truncation of File Exploit

/ XNU has various interfaces that permit creating copy-on-write copies of data between processes, including out-of-line message descriptors in mach messages. It is important that the copied memory is protected against later modifications by the source process; otherwise, the source process might ...

macOS < 10.14.3 / iOS < 12.1.3 XNU - vm_map_copy Optimization which Requires Atomicity isn&#0

/ vmmapcopyininternal in vmmap.c converts a region of a vmmap into "copied in" form, constructing a vmmapcopy structure representing the copied memory which can then be mapped into another vmmap or the same one. The function contains a while loop which walks through each of the vmmapentry...

macOS XNU - Copy-on-Write Behaviour Bypass via Partial-Page Truncation of File

macOS XNU - Copy-on-Write Behaviour Bypass via Partial-Page Truncation of File / XNU has various interfaces that permit creating copy-on-write copies of data between processes, including out-of-line message descriptors in mach messages. It is important that the copied memory is protected against...

macOS 10.14.3 iOS 12.1.3 XNU - vm_map_copy Optimization which Requires Atomicity isnt Atomic

macOS 10.14.3 iOS 12.1.3 XNU - vmmapcopy Optimization which Requires Atomicity isnt Atomic / vmmapcopyininternal in vmmap.c converts a region of a vmmap into "copied in" form, constructing a vmmapcopy structure representing the copied memory which can then be mapped into another vmmap or the same...

macOS < 10.14.3 / iOS < 12.1.3 XNU - 'vm_map_copy' Optimization which Requires Atomicity isn't Atomic

/ vmmapcopyininternal in vmmap.c converts a region of a vmmap into "copied in" form, constructing a vmmapcopy structure representing the copied memory which can then be mapped into another vmmap or the same one. The function contains a while loop which walks through each of the vmmapentry...

macOS XNU - Copy-on-Write Behaviour Bypass via Partial-Page Truncation of File

/ XNU has various interfaces that permit creating copy-on-write copies of data between processes, including out-of-line message descriptors in mach messages. It is important that the copied memory is protected against later modifications by the source process; otherwise, the source process might ...

voucher_swap: Exploiting MIG reference counting in iOS 12

Posted by Brandon Azad, Project Zero In this post I'll describe how I discovered and exploited CVE-2019-6225, a MIG reference counting vulnerability in XNU's taskswapmachvoucher function. We'll see how to exploit this bug on iOS 12.1.2 to build a fake kernel task port, giving us the ability to re...

XNU - POSIX Shared Memory Mappings have Incorrect Maximum Protection

XNU - POSIX Shared Memory Mappings have Incorrect Maximum Protection When the mmap syscall is invoked on a POSIX shared memory segment DTYPEPSXSHM, pshmmmap maps the shared memory segment's pages into the address space of the calling process. It does this with the following code: int prot =...

XNU POSIX Shared Memory Mapping Issue Exploit

Exploit for multiple platform in category local exploits XNU: POSIX shared memory mappings have incorrect maximum protection CVE-2018-4435 When the mmap syscall is invoked on a POSIX shared memory segment DTYPEPSXSHM, pshmmmap maps the shared memory segment's pages into the address space of the...

XNU POSIX Shared Memory Mapping Issue

XNU: POSIX shared memory mappings have incorrect maximum protection CVE-2018-4435 When the mmap syscall is invoked on a POSIX shared memory segment DTYPEPSXSHM, pshmmmap maps the shared memory segment's pages into the address space of the calling process. It does this with the following code: int...

XNU - POSIX Shared Memory Mappings have Incorrect Maximum Protection

When the mmap syscall is invoked on a POSIX shared memory segment DTYPEPSXSHM, pshmmmap maps the shared memory segment's pages into the address space of the calling process. It does this with the following code: int prot = uap-prot; ... if prot & PROTWRITE && fp-fflag & FWRITE == 0 returnEPERM;...

XNU Kernel iOS / macOS heap buffer overflow Exploit

The vulnerability is a heap buffer overflow in the networking code in the XNU operating system kernel. XNU is used by both iOS and macOS, which is why iPhones, iPads, and Macbooks are all affected. My exploit PoC just overwrites the heap with garbage, which causes an immediate kernel crash and...

Apple iOS/macOS - Sandbox Escape due to mach Message sent from Shared Memory

iohideventsystem sets up a shared memory event queue; at the end of this shared memory buffer it puts a mach message which it sends whenever it wants to notify a client that there's data available in the queue. As a client we can modify this mach message such that the server hidd on MacOS,...

XNU kernel heap overflow due to bad bounds checking in MPTCP(CVE-2018-4241)

mptcpusrconnectx is the handler for the connectx syscall for the APMULTIPATH socket family. The logic of this function fails to correctly handle source and destination sockaddrs which aren't AFINET or AFINET6: // verify salen for AFINET: if dst-safamily == AFINET && dst-salen !=...

XNU Kernel - Heap Overflow Due to Bad Bounds Checking in MPTCP

mptcpusrconnectx is the handler for the connectx syscall for the APMULTIPATH socket family. The logic of this function fails to correctly handle source and destination sockaddrs which aren't AFINET or AFINET6: // verify salen for AFINET: if dst-safamily == AFINET && dst-salen !=...

XNU Kernel - Heap Overflow Due to Bad Bounds Checking in MPTCP

XNU Kernel - Heap Overflow Due to Bad Bounds Checking in MPTCP mptcpusrconnectx is the handler for the connectx syscall for the APMULTIPATH socket family. The logic of this function fails to correctly handle source and destination sockaddrs which aren't AFINET or AFINET6: // verify salen for...

XNU Kernel - Heap Overflow Due to Bad Bounds Checking in MPTCP Exploit

Exploit for multiple platform in category dos / poc mptcpusrconnectx is the handler for the connectx syscall for the APMULTIPATH socket family. The logic of this function fails to correctly handle source and destination sockaddrs which aren't AFINET or AFINET6: // verify salen for AFINET: if...

Apple macOS HighSierra 10.13 - ctl_ctloutput-leak Information Leak Exploit

Exploit for macOS platform in category local exploits / ctlctloutput-leak.c Brandon Azad CVE-2017-13868 While looking through the source code of XNU version 4570.1.46, I noticed that the function ctlctloutput in the file bsd/kern/kerncontrol.c does not check the return value of sooptcopyin, which...

Apple macOS XNU Kernel - Memory Disclosure due to bug in Kernel API for Detecting Kernel Memory Disclosures

/ Source: https://bugs.chromium.org/p/project-zero/issues/detail?id=1372 the kernel libproc API proclistuptrs has the following comment in it's userspace header: / Enumerate potential userspace pointers embedded in kernel data structures. Currently inspects kqueues only. NOTE: returned "pointers"...

Apple macOS XNU Kernel - Memory Disclosure due to bug in Kernel API for Detecting Kernel Memory Disclosures

Apple macOS XNU Kernel - Memory Disclosure due to bug in Kernel API for Detecting Kernel Memory Disclosures / Source: https://bugs.chromium.org/p/project-zero/issues/detail?id=1372 the kernel libproc API proclistuptrs has the following comment in it's userspace header: / Enumerate potential...