Thilan Dissanayaka Exploit development Apr 12, 2026

Exploiting a heap buffer overflow in linux

In the previous article, we dissected glibc's malloc — chunks, bins, tcache, coalescing, and the metadata that holds it all together. Now we break it.

Heap exploitation is fundamentally different from stack exploitation. On the stack, the goal is clear: overwrite the return address, control EIP. On the heap, there's no return address to overwrite. Instead, we corrupt the allocator's metadata to trick malloc() into returning a pointer to memory we want to control — a function pointer, a GOT entry, a vtable, or any other target.

SQL Injection Login Bypass

SQL Injection (SQLi) is one of the oldest and most fundamental web application vulnerabilities. While modern frameworks have made it harder to introduce, understanding SQL injection is essential for anyone learning web security. In this post, we'll break it down from the ground up using a classic login bypass.

Feb 14 Application Security

Out of Band SQL Injection

Out of Band SQL Injection (OOB SQLi) is an advanced SQL injection technique where the attacker cannot retrieve data directly through the same communication channel used to send the injection payload....

Apr 12 Exploit development

Exploiting a format string vulnerebility on Linux

A misused printf can leak stack contents, read arbitrary memory, and write to arbitrary addresses. Format string vulnerabilities are one of the most powerful bug classes in C and they're the key to defeating ASLR. In this post, we exploit printf from leak to shell.

Apr 12 Exploit development

Exploiting a heap buffer overflow in linux

In the [previous article](/heap-internals-how-glibc-malloc-works/), we dissected glibc's malloc — chunks, bins, tcache, coalescing, and the metadata that holds it all together. Now we break...

Jan 27 Software Architecture

Singleton Pattern explained simply

Ever needed just one instance of a class in your application? Maybe a logger, a database connection, or a configuration manager? This is where the Singleton Pattern comes in — one of the simplest but...

Apr 05 Exploit development

Bypassing DEP with Return-to-libc

DEP makes the stack non-executable — our shellcode can't run. The simplest bypass? Don't inject code at all. Instead, call functions that already exist in libc. In this post, we exploit a stack overflow to call system('/bin/sh') without writing a single byte of shellcode.