Introduction

In this post, I will introduce CVE-2017-3000, a CVE assigned to us last year. We analyse the weak implementation of the PRNG in Flash Player, which is used for constant blinding in its JIT compiler. We find two methods circumventing the constant blinding. Furthermore, we give a detailed exploitation plan on how to insert desired value into JIT code even if constant blinding is in place as demonstrated on the cover page. In this post, I will give details on the design of the PRNG and full exploit based on CVE-2015-5122.
Read More »

Introduction

In this post, I will give a full COOP-like exploit based on CVE-2015-5119 as demonstrated on cover page. This post will contain two parts. The first part is about how to achieve arbitrary read/write primitive in 64-bit Flash. This part is based on [1][2] with some extra my own explanations. The second part is about how to achieve a COOP-like exploit with virtual function gadgets. I will discuss the dispatcher gadget, argument loading gadget and invoking gadget used in the exploit and pop up the calculator in the end. So I will skip the analysis of root cause of the vulnerability and focus on exploit development.
Read More »

Introduction

This is a use-after-use vulnerability in the firefox before 50.2 [1]. In this post, the exploit is a routine browser exploitation process. Since exploit [1] is a working exploit on windows platform, I rewrite the exploit to make it work on Linux platform and test some ideas on vtable reuse attacks. I use a chain of multiple virtual function gadgets to change memory protection and open a listening port or popping up calculator. The final exploit can be found on my github repo[3].
Read More »

Introduction

In this post, I will give a detailed explanation on the exploit development of CVE-2017-16995. This post is based on [1][2][3] and give more debugging information for a better understanding. This post will be divided into 3 parts. Part I will discuss what is eBPF, the basic data structure used in eBPF and how the the eBPF program given in exploit in [1] should be interpreted. Part II will give the analysis on the root cause of this vulnerability. Part III will explain how the exploit is developed, from arbitrary read/write to privilege escalation.Read More »

Introduction

This vulnerability is an integer overflow vulnerability, which involves a signed comparison between a signed integer and an unsigned integer and results in out-of-bound read. The analysis on root cause has already been available online [2][3]. But these talk few about how they locate the root cause in the binary starting from zero knowledge. In this post, I hope to log how I locate the root cause of the vulnerability starting from the crash. Therefore, the post may look tedious but I will try to demonstrate every step I take in my analysis.Read More »

Introduction

This is a integer overflow vulnerability in Linux Kernel. The exploit code can be found on [1]. This post will mainly discuss on the root cause of this CVE and how the exploit works in the end.Read More »

CVE-2017-14497

Introduction

Recently I was taking a research on Linux kernel vulnerability and kernel fuzzing. CVE-2017-14497 is a Linux Kernel Oops that affects Linux Kernel before Linux-4.13-rc2. This post will give a detailed analysis on the crash.Read More »