Company
Date Published
Author
Kevin Backhouse
Word count
1566
Language
English
Hacker News points
None

Summary

In this third post of a four-part series, security researcher Kevin Backhouse delves into the apport CVE-2019-15790 vulnerability, which allows a local attacker to obtain ASLR offsets of any process they can control. The vulnerability arises from using PIDs as authorization tokens, which can be recycled and reassigned, enabling attackers to trick apport into leaking sensitive information. Backhouse explores two exploitation plans, with the second, Plan B, proving successful. This plan involves deliberately crashing an innocuous process to manipulate the PID recycling system, allowing a privileged process to be assigned the same PID. By pausing apport during this transition, Backhouse accesses sensitive information from the /proc/[pid]/maps file, crucial for gaining ASLR offsets. This exploit is part of a broader strategy targeting the whoopsie daemon, which will be further explored in the final post of the series, focusing on exploiting a heap buffer overflow vulnerability to gain code execution.