Apple macOS 10.14.5 iOS 12.3 XNU - Wild-read due to bad cast in stf_ioctl

Apple macOS 10.14.5 iOS 12.3 XNU - Wild-read due to bad cast in stfioctl / Reproduction Tested on macOS 10.14.3: $ clang -o stfwildread stfwildread.cc $ ./stfwildread Explanation SIOCSIFADDR is an ioctl that sets the address of an interface. The stf interface ioctls are handled by the stfioctl...

macOS < 10.14.5 / iOS < 12.3 XNU - Wild-read due to bad cast in stf_ioctl Exploit

macOS ifaaddr-safamily != AFINET6 // - crash here IFAUNLOCKifa; error = EAFNOSUPPORT; break; Note that IFALOCK is called on user-provided data; it appears that there is an opportunity for memory corruption a controlled write when using indirect mutexes via LCKMTXTAGINDIRECT see lckmtxlockslow...

Apple macOS 10.14.5 iOS 12.3 XNU - in6_pcbdetach Stale Pointer Use-After-Free

Apple macOS 10.14.5 iOS 12.3 XNU - in6pcbdetach Stale Pointer Use-After-Free Reproduction Repros on 10.14.3 when run as root. It may need multiple tries to trigger. $ clang -o in6selectsrc in6selectsrc.cc $ while 1; do sudo ./in6selectsrc; done res0: 3 res1: 0 res1.5: -1 // failure expected here...

XNU Stale Pointer Use-After-Free

XNU: Use-after-free due to stale pointer left by in6pcbdetach Related CVE Numbers: CVE-2019-8605Fixed-2019-May-13. Reproduction Repros on 10.14.3 when run as root. It may need multiple tries to trigger. $ clang -o in6selectsrc in6selectsrc.cc $ while 1; do sudo ./in6selectsrc; done res0: 3 res1: ...

Apple macOS < 10.14.5 / iOS < 12.3 XNU - 'in6_pcbdetach' Stale Pointer Use-After-Free

Reproduction Repros on 10.14.3 when run as root. It may need multiple tries to trigger. $ clang -o in6selectsrc in6selectsrc.cc $ while 1; do sudo ./in6selectsrc; done res0: 3 res1: 0 res1.5: -1 // failure expected here res2: 0 done ... crash Explanation The following snippet is taken from...

Apple macOS < 10.14.5 / iOS < 12.3 XNU - Wild-read due to bad cast in stf_ioctl

/ Reproduction Tested on macOS 10.14.3: $ clang -o stfwildread stfwildread.cc $ ./stfwildread Explanation SIOCSIFADDR is an ioctl that sets the address of an interface. The stf interface ioctls are handled by the stfioctl function. The crash occurs in the following case where a struct ifreq is re...

iOS 12.2 macOS 10.14.4 XNU - pidversion Increment During execve is Unsafe

iOS 12.2 macOS 10.14.4 XNU - pidversion Increment During execve is Unsafe Privileged IPC services in userspace often have to verify the security context of their client processes such as whether the client is sandboxed, has a specific entitlement, or is signed by some code signing authority. This...

iOS < 12.2 / macOS < 10.14.4 XNU - pidversion Increment During execve is Unsafe Exploit

iOS 12.2 / macOS 10.14.4 XNU - pidversion Increment During execve is Unsafe Exploit Privileged IPC services in userspace often have to verify the security context of their client processes such as whether the client is sandboxed, has a specific entitlement, or is signed by some code signing...

Splitting atoms in XNU

Posted by Ian Beer, Google Project Zero TL;DR A locking bug in the XNU virtual memory subsystem allowed violation of the preconditions required for the correctness of an optimized virtual memory operation. This was abused to create shared memory where it wasn't expected, allowing the creation of ...

Project Zero Discloses High-Severity Apple macOS Flaw

Researchers have disclosed what they say is a high-severity security flaw in Apple’s MacOS operating system – which has not yet been patched. The flaw gives an attacker privileges to perform malicious actions on a mounted filesystem – without the victim knowing. The Google Project Zero team...

macOS XNU - Copy-on-Write Behavior #Bypass via Mount of User-Owned Filesystem Image 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 be...

macOS XNU - Copy-on-Write Behavior Bypass via Mount of User-Owned Filesystem Image

macOS XNU - Copy-on-Write Behavior Bypass via Mount of User-Owned Filesystem Image 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 agains...

macOS XNU - Copy-on-Write Behavior Bypass via Mount of User-Owned Filesystem Image

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 be...

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 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 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 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 ...

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...

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...