Source: https://code.google.com/p/google-security-research/issues/detail?id=478
The Install.framework runner suid root binary does not correctly account for the fact that Distributed Objects
can be connected to by multiple clients at the same time.
By connecting two proxy objects to an IFInstallRunner and calling [IFInstallRunner makeReceiptDirAt:asRoot:]
in the first and passing a custom object as the directory name we can get a callback to our code just after the
makeReceiptDirAt code has called seteuid(0);setguid(0) to regain privs. Since BSD priviledges are per-process
this means that our other proxy object will now have euid 0 without having to provide an authorization reference.
In this second proxy we can then just call runTaskSecurely and get a root shell before returning from the first proxy's callback function
which will then drop privs.
build using the provided makefile and run passing the full path to the localhost shell
Proof of Concept:
https://github.com/offensive-security/exploitdb-bin-sploits/raw/master/bin-sploits/38136.zipData
Build on a solid foundation with Vulners data
We provide the essential building blocks for cybersecurity solutions with comprehensive, structured, and constantly updated vulnerability and exploits data
Api
Power your application with Vulners API
The Vulners REST API offers reliable, high-performance access to vulnerability intelligence, with 99.9% SLA uptime and CDN-backed data delivery for seamless global access
App
Assess and manage vulnerabilities with Vulners tools
Built on top of Vulners' database and SDK, end-user solutions give security professionals and developers lightweight and powerful tools for vulnerability remediation