CAPEC Details
Name Leveraging Race Conditions
Likelyhood of attack Typical severity
High High
Summary The adversary targets a race condition occurring when multiple processes access and manipulate the same resource concurrently, and the outcome of the execution depends on the particular order in which the access takes place. The adversary can leverage a race condition by "running the race", modifying the resource and modifying the normal execution flow. For instance, a race condition can occur while accessing a file: the adversary can trick the system by replacing the original file with their version and cause the system to read the malicious file.
Prerequisites A resource is accessed/modified concurrently by multiple processes such that a race condition exists. The adversary has the ability to modify the resource.
Execution Flow
Step Phase Description Techniques
1 Explore The adversary explores to gauge what level of access they have.
2 Experiment The adversary gains access to a resource on the target host. The adversary modifies the targeted resource. The resource's value is used to determine the next normal execution action.
3 Exploit The resource is modified/checked concurrently by multiple processes. By using one of the processes, the adversary is able to modify the value just before it is consumed by a different process. A race condition occurs and is exploited by the adversary to abuse the target host.
Solutions Use safe libraries to access resources such as files. Be aware that improper use of access function calls such as chown(), tempfile(), chmod(), etc. can cause a race condition. Use synchronization to control the flow of execution. Use static analysis tools to find race conditions. Pay attention to concurrency problems related to the access of resources.
Related Weaknesses
CWE ID Description
CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CWE-363 Race Condition Enabling Link Following
CWE-366 Race Condition within a Thread
CWE-368 Context Switching Race Condition
CWE-370 Missing Check for Certificate Revocation after Initial Check
CWE-662 Improper Synchronization
CWE-665 Improper Initialization
CWE-667 Improper Locking
CWE-689 Permission Race Condition During Resource Copy
CWE-1223 Race Condition for Write-Once Attributes