Exploit Methods/Userspace data usage

Details

Sometimes an attacker won't be able to control the instruction pointer directly, but they will be able to redirect the dereference a structure or other pointer. In these cases, it is easiest to aim at malicious structures that have been built in userspace to perform the exploitation.

Examples

• cred structure
• fake kernel stack
• Bad casts

Mitigations

• hardware segmentation: SMAP (x86), PAN (arm, arm64), Domains (arm)
• emulate memory segmentation via separate page tables (e.g. PAX_UDEREF)