The product utilizes multiple threads or processes to allow temporary access to a shared resource that can only be exclusive to one process at a time, but it does not properly synchronize these actions, which might cause simultaneous accesses of this resource by multiple threads or processes.
Synchronization refers to a variety of behaviors and mechanisms that allow two or more independently-operating processes or threads to ensure that they operate on shared resources in predictable ways that do not interfere with each other. Some shared resource operations cannot be executed atomically; that is, multiple steps must be guaranteed to execute sequentially, without any interference by other processes. Synchronization mechanisms vary widely, but they may include locking, mutexes, and semaphores. When a multi-step operation on a shared resource cannot be guaranteed to execute independent of interference, then the resulting behavior can be unpredictable. Improper synchronization could lead to data or memory corruption, denial of service, etc.
Threat Mapped score: 1.9
Industry: Finiancial
Threat priority: P3 - Important (Medium)
CVE: CVE-2021-1782 — KEV
Chain: improper locking (CWE-667) leads to race condition (CWE-362), as exploited in the wild per CISA KEV.
CVE: CVE-2009-0935
Attacker provides invalid address to a memory-reading function, causing a mutex to be unlocked twice
| Phase | Note |
|---|---|
| Architecture and Design | N/A |
| Implementation | N/A |
Intro: The following function attempts to acquire a lock in order to perform operations on a shared resource.
Body: However, the code does not check the value returned by pthread_mutex_lock() for errors. If pthread_mutex_lock() cannot acquire the mutex for any reason, the function may introduce a race condition into the program and result in undefined behavior.
void f(pthread_mutex_t *mutex) { pthread_mutex_lock(mutex); /* access shared resource */ pthread_mutex_unlock(mutex); }Intro: The following code intends to fork a process, then have both the parent and child processes print a single line.
Body: One might expect the code to print out something like:
static void print (char * string) { char * word; int counter; for (word = string; counter = *word++; ) { putc(counter, stdout); fflush(stdout); /* Make timing window a little larger... */ sleep(1); } } int main(void) { pid_t pid; pid = fork(); if (pid == -1) { exit(-2); } else if (pid == 0) { print("child\n"); } else { print("PARENT\n"); } exit(0); }