CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.

• Availability: DoS: Resource Consumption (CPU), DoS: Resource Consumption (Memory), DoS: Resource Consumption (Other) — When a race condition makes it possible to bypass a resource cleanup routine or trigger multiple initialization routines, it may lead to resource exhaustion. • Availability: DoS: Crash, Exit, or Restart, DoS: Instability — When a race condition allows multiple control flows to access a resource simultaneously, it might lead the product(s) into unexpected states, possibly resulting in a crash. • Confidentiality, Integrity: Read Files or Directories, Read Application Data — When a race condition is combined with predictable resource names and loose permissions, it may be possible for an attacker to overwrite or access confidential data (CWE-59). • Access Control: Execute Unauthorized Code or Commands, Gain Privileges or Assume Identity, Bypass Protection Mechanism — This can have security implications when the expected synchronization is in security-critical code, such as recording whether a user is authenticated or modifying important state information that should not be influenced by an outsider.

• [Architecture and Design] In languages that support it, use synchronization primitives. Only wrap these around critical code to minimize the impact on performance. • [Architecture and Design] Use thread-safe capabilities such as the data access abstraction in Spring. • [Architecture and Design] Minimize the usage of shared resources in order to remove as much complexity as possible from the control flow and to reduce the likelihood of unexpected conditions occurring. Additionally, this will minimize the amount of synchronization necessary and may even help to reduce the likelihood of a denial of service where an attacker may be able to repeatedly trigger a critical section (CWE-400). • [Implementation] When using multithreading and operating on shared variables, only use thread-safe functions. • [Implementation] Use atomic operations on shared variables. Be wary of innocent-looking constructs such as "x++". This may appear atomic at the code layer, but it is actually non-atomic at the instruction layer, since it involves a read, followed by a computation, followed by a write. • [Implementation] Use a mutex if available, but be sure to avoid related weaknesses such as CWE-412. • [Implementation] Avoid double-checked locking (CWE-609) and other implementation errors that arise when trying to avoid the overhead of synchronization. • [Implementation] Disable interrupts or signals over critical parts of the code, but also make sure that the code does not go into a large or infinite loop. • [Implementation] Use the volatile type modifier for critical variables to avoid unexpected compiler optimization or reordering. This does not necessarily solve the synchronization problem, but it can help. • [Architecture and Design, Operation] Run your code using the lowest privileges that are required to accomplish the necessary tasks [REF-76]. If possible, create isolated accounts with limited privileges that are only used for a single task. That way, a successful attack will not immediately give the attacker access to the rest of the software or its environment. For example, database applications rarely need to run as the database administrator, especially in day-to-day operations.

• Black Box: Black box methods may be able to identify evidence of race conditions via methods such as multiple simultaneous connections, which may cause the software to become instable or crash. However, race conditions with very narrow timing windows would not be detectable. • White Box: Common idioms are detectable in white box analysis, such as time-of-check-time-of-use (TOCTOU) file operations (CWE-367), or double-checked locking (CWE-609). • Automated Dynamic Analysis: This weakness can be detected using dynamic tools and techniques that interact with the software using large test suites with many diverse inputs, such as fuzz testing (fuzzing), robustness testing, and fault injection. The software's operation may slow down, but it should not become unstable, crash, or generate incorrect results. Race conditions may be detected with a stress-test by calling the software simultaneously from a large number of threads or processes, and look for evidence of any unexpected behavior. Insert breakpoints or delays in between relevant code statements to artificially expand the race window so that it will be easier to detect. • Automated Static Analysis - Binary or Bytecode: According to SOAR [REF-1479], the following detection techniques may be useful: Highly cost effective: • Bytecode Weakness Analysis - including disassembler + source code weakness analysis Cost effective for partial coverage: • Binary Weakness Analysis - including disassembler + source code weakness analysis • Dynamic Analysis with Automated Results Interpretation: According to SOAR [REF-1479], the following detection techniques may be useful: Cost effective for partial coverage: • Web Application Scanner • Web Services Scanner • Database Scanners • Dynamic Analysis with Manual Results Interpretation: According to SOAR [REF-1479], the following detection techniques may be useful: Highly cost effective: • Framework-based Fuzzer Cost effective for partial coverage: • Fuzz Tester • Monitored Virtual Environment - run potentially malicious code in sandbox / wrapper / virtual machine, see if it does anything suspicious • Manual Static Analysis - Source Code: According to SOAR [REF-1479], the following detection techniques may be useful: Highly cost effective: • Manual Source Code Review (not inspections) Cost effective for partial coverage: • Focused Manual Spotcheck - Focused manual analysis of source • Automated Static Analysis - Source Code: According to SOAR [REF-1479], the following detection techniques may be useful: Highly cost effective: • Source code Weakness Analyzer • Context-configured Source Code Weakness Analyzer • Architecture or Design Review: According to SOAR [REF-1479], the following detection techniques may be useful: Highly cost effective: • Formal Methods / Correct-By-Construction Cost effective for partial coverage: • Inspection (IEEE 1028 standard) (can apply to requirements, design, source code, etc.)

• CVE-2024-38106: OS kernel stores sensitive data in improperly locked memory, allowing local users to gain privileges by winning a race condition • CVE-2022-29527: Go application for cloud management creates a world-writable sudoers file that allows local attackers to inject sudo rules and escalate privileges to root by winning a race condition. • CVE-2021-1782: Chain: improper locking (CWE-667) leads to race condition (CWE-362), as exploited in the wild per CISA KEV. • CVE-2021-0920: Chain: mobile platform race condition (CWE-362) leading to use-after-free (CWE-416), as exploited in the wild per CISA KEV. • CVE-2020-6819: Chain: race condition (CWE-362) leads to use-after-free (CWE-416), as exploited in the wild per CISA KEV. • CVE-2019-18827: Chain: JTAG interface is not disabled (CWE-1191) during ROM code execution, introducing a race condition (CWE-362) to extract encryption keys • CVE-2019-1161: Chain: race condition (CWE-362) in anti-malware product allows deletion of files by creating a junction (CWE-1386) and using hard links during the time window in which a temporary file is created and deleted. • CVE-2015-1743: TOCTOU in sandbox process allows installation of untrusted browser add-ons by replacing a file after it has been verified, but before it is executed • CVE-2014-8273: Chain: chipset has a race condition (CWE-362) between when an interrupt handler detects an attempt to write-enable the BIOS (in violation of the lock bit), and when the handler resets the write-enable bit back to 0, allowing attackers to issue BIOS writes during the timing window [REF-1237]. • CVE-2008-5044: Race condition leading to a crash by calling a hook removal procedure while other activities are occurring at the same time. • CVE-2008-2958: Chain: time-of-check time-of-use (TOCTOU) race condition in program allows bypass of protection mechanism that was designed to prevent symlink attacks. • CVE-2008-1570: Chain: time-of-check time-of-use (TOCTOU) race condition in program allows bypass of protection mechanism that was designed to prevent symlink attacks. • CVE-2008-0058: Unsynchronized caching operation enables a race condition that causes messages to be sent to a deallocated object. • CVE-2008-0379: Race condition during initialization triggers a buffer overflow. • CVE-2007-6599: Daemon crash by quickly performing operations and undoing them, which eventually leads to an operation that does not acquire a lock. • CVE-2007-6180: Chain: race condition triggers NULL pointer dereference • CVE-2007-5794: Race condition in library function could cause data to be sent to the wrong process. • CVE-2007-3970: Race condition in file parser leads to heap corruption. • CVE-2008-5021: Composite: race condition (CWE-362) allows attacker to modify an object while it is still being initialized, causing software to access uninitialized memory (CWE-908). • CVE-2009-4895: Chain: race condition for an argument value, possibly resulting in NULL dereference • CVE-2009-3547: Chain: race condition (CWE-362) might allow resource to be released before operating on it, leading to NULL dereference (CWE-476) • CVE-2006-5051: Chain: Signal handler contains too much functionality (CWE-828), introducing a race condition (CWE-362) that leads to a double free (CWE-415).