What flaw occurs when a multithreaded application fails to properly handle threads accessing a common value?

The flaw that occurs when a multithreaded application fails to properly handle threads accessing a common value is known as a race condition. In this scenario, multiple threads are trying to read from and write to shared data concurrently without proper synchronization mechanisms in place. This can lead to unpredictable behavior and inconsistent results, as the final outcome may depend on the timing of when each thread accesses the shared variable.

Race conditions typically occur in environments where there are shared resources and the threads operate independently and concurrently. To mitigate such issues, developers can implement synchronization techniques such as locks, semaphores, or mutexes to control access to the shared resource, ensuring that only one thread can access the critical section of code at a time, which reduces the chances of data inconsistency.

In contrast, time-of-check/time-of-use vulnerabilities involve a different issue regarding the state of data during the verification process before it is used, while buffer overflow refers to an event where data exceeds the allocated buffer size causing overflow into adjacent memory. Integer overflow occurs when an integer value exceeds its maximum limit, wrapping around to a negative or zero value. Each of these concepts has its distinct implications within the realm of software security.