CWE-567: Unsynchronized Access to Shared Data in a… | Glexia
CWE-567 (Unsynchronized Access to Shared Data in a Multithreaded Context) weakness overview with consequences, detection methods, mitigations, related CVEs and…
Glexia's Take · Automated analysis
CWE-567: Unsynchronized Access to Shared Data in a Multithreaded Context
Unsynchronized Access to Shared Data in a Multithreaded Context represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Executive Impact
- Confidentiality,Integrity,Availability: Read Application Data,Modify Application Data,DoS: Instability,DoS: Crash, Exit, or Restart: If the shared variable contains sensitive data, it may be manipulated or displayed in another user session. If this data is used to control the application, its value can be manipulated to cause the application to crash or perform poorly.
Developer Pattern
CWE-567 is the kind of defect developers can usually prevent with explicit validation, safer framework defaults, and tests that exercise hostile input or unsafe state transitions.
Automation confidence
high confidence from CWE-567, 4.20.
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Official CWE Definition
CWE-567: Unsynchronized Access to Shared Data in a Multithreaded Context
The product does not properly synchronize shared data, such as static variables across threads, which can lead to undefined behavior and unpredictable data changes.
Developer And Remediation Guidance
How teams prevent and detect this weakness
Causes
- The following code implements a basic counter for how many times the page has been accesed. Consider when two separate threads, Thread A and Thread B, concurrently handle two different requests:, ,At this point, both Thread A and Thread B print that one hit has been seen, even though two separate requests have been processed. The value of count should be 2, not 1.,While this example does not have any real serious implications, if the shared variable in question is used for resource tracking, then resource consumption could occur. Other scenarios exist.
Remediation
- Implementation: Remove the use of static variables used between servlets. If this cannot be avoided, use synchronized access for these variables.
Detection
- Automated Static Analysis: Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)
Mappings
Related CVEs, CWEs, and ATT&CK context
Related CWEs
No related CWE relationships are published yet.
ATT&CK Relevance
ATT&CK relevance is shown only when reviewed or responsibly inferred.