Sophos SafeGuard Enterprise before 8.00.5, SafeGuard Easy before 7.00.3, and SafeGuard LAN Crypt before 3.95.2 are vulnerable to Local Privilege Escalation via IOCTL 0x80206040. By crafting an input buffer we can control the execution path to the point where the constant DWORD 0 will be written to a user-controlled address. We can take advantage of this condition to zero-out the pointer to the security descriptor in the object header of a privileged process or modify the security descriptor itself and run code in the context of a process running as SYSTEM.
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.
| Link | Tags |
|---|---|
| https://community.sophos.com/kb/en-us/131934 | patch vendor advisory |
| http://seclists.org/fulldisclosure/2018/Jul/20 | third party advisory mailing list |
| https://labs.nettitude.com/blog/cve-2018-6851-to-cve-2018-6857-sophos-privilege-escalation-vulnerabilities/ | exploit third party advisory technical description |