Heap spraying

Heap spraying is a form of memory attack that involves overwriting a target computer’s memory with an intentional payload of malicious code. The malicious code is then used to increase the chances of a successful attack, as it simplifies the process of exploiting a vulnerability within a computer system. Heap spraying works by taking advantage of the fact that the heap is allocated contiguously. By having the malicious code reside on the heap, attackers can be sure that when the vulnerable code is run, it is more likely to execute their arbitrary code.

Heap spraying has been used in numerous attacks that exploit memory corruption, privilege escalation, or other software vulnerabilities. Common targets for heap spraying attacks include PDF readers, web browsers, and office applications such as Word and Excel. Despite the fact that heap spraying is seen as a challenging form of attack, it has remained an important tool in the arsenal of an attacker, as it can allow successful exploitation of a system even when other attack vectors have been blocked.

Heap spraying is also sometimes referred to as heap allocation or heap over write attack. Such an attack may be used in combination with a multiple buffer overflow, where multiple instances of the same input will force the system to overwrite the same allocated heap memory area, which would eventually execute the malicious payload.

Heap spraying is a well-known strategy to successfully exploit a vulnerable application, and so developers should build and deploy code with heap and memory management optimizations, as well as techniques to make it difficult or impossible to spray the heap. Additionally, developers should use secure coding practices to test the application for vulnerabilities. Cybersecurity professionals can also use preventive measures, such as regularly updating their software, to mitigate the risk of a heap spraying attack.