Buffer Overrun
A buffer overrun calls for a lot of concern because it is considered as one of primary sources that cause security risk. A buffer overrun can occur on any computer and is normally caused when you treat any unchecked data or external input as reliable data. Normally, when you visit the internet and try to open a web page, there are some pages that will show a message stating unreliable data. Most of the times you may click on ok and proceed with the opening of the page because you feel what harm can the data do. This is exactly similar to how a buffer overrun really happens.
When you copy unreliable data using different operations like strcat, CopyMemory, wcscpy or strcpythen it leads to the creation of unanticipated results that further leads to system corruption and you get the buffer overrun error. In some of the cases, an application will automatically abort with a segmentation fault, core dump, or access violation. But when we are talking of the worse case scenario in buffer overrun then it means that an attacker will be able to take advantage of the buffer overrun error and execute their malicious codes into your system process. The most common cause of various exploitable errors or faults is copying of various unchecked input data into the stack-based buffer.
Buffer Overrun Situations
A buffer overrun can take place in different situations and here are some of the situations:
Static buffer overruns
A static buffer overrun takes place when a buffer declared on a stack is introduced to more data than its actual capacity. It can also occur when an unverified user input data gets copied directly to the static variable, which can further lead to a stack corruption.
Heap overruns
Heap overruns is a type of buffer overrun and are quite similar to the static buffer overruns. When a heap overrun occurs, it might cause stack corruption and memory corruption. Heap overruns always take place in heap memory and not on stack memory. Although it might not cause as serious a problem as stack buffer overruns can cause yet it is recommended that they need real programming care, which might mitigate the potential risks.
Array indexing errors
The array indexing errors cause memory overruns. They cause a different type of buffer overrun as compared to the static and heap overrun errors. The only way to prevent this error is through careful index management.
The only way to prevent a buffer overrun is by writing a good code. Whenever it comes to the code, ensure that you have validated all your inputs. It is important to always maintain a high degree of correct programming for the safety of the memory and stack on your PC.
