CWE-1023: Incomplete Comparison with Missing Factors
Official CWE-1023 CWE context with Glexia analysis, remediation guidance, related CVEs, and ATT&CK context.
Glexia's Take
CWE-1023: Incomplete Comparison with Missing Factors
Incomplete Comparison with Missing Factors represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Executive Impact
- Integrity,Access Control: Alter Execution Logic,Bypass Protection Mechanism: An incomplete comparison can lead to resultant weaknesses, e.g., by operating on the wrong object or making a security decision without considering a required factor.
Developer Pattern
CWE-1023 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.
Confidence
high confidence from CWE-1023, 4.20.
Official CWE Definition
CWE-1023: Incomplete Comparison with Missing Factors
The product performs a comparison between entities that must consider multiple factors or characteristics of each entity, but the comparison does not include one or more of these factors.
Developer And Remediation Guidance
How teams prevent and detect this weakness
Causes
- Consider an application in which Truck objects are defined to be the same if they have the same make, the same model, and were manufactured in the same year. Here, the equals() method only checks the make and model of the Truck objects, but the year of manufacture is not included.
- This example defines a fixed username and password. The AuthenticateUser() function is intended to accept a username and a password from an untrusted user, and check to ensure that it matches the username and password. If the username and password match, AuthenticateUser() is intended to indicate that authentication succeeded. In AuthenticateUser(), the strncmp() call uses the string length of an attacker-provided inPass parameter in order to determine how many characters to check in the password. So, if the attacker only provides a password of length 1, the check will only examine the first byte of the application's password before determining success.,As a result, this partial comparison leads to improper authentication (CWE-287).,Any of these passwords would still cause authentication to succeed for the "admin" user:,This significantly reduces the search space for an attacker, making brute force attacks more feasible.,The same problem also applies to the username, so values such as "a" and "adm" will succeed for the username.,While this demonstrative example may not seem realistic, see the Observed Examples for CVE entries that effectively reflect this same weakness.
Remediation
- Use safe APIs
- Centralize the control
- Add regression tests
- Review logs and telemetry for attempted abuse
Detection
- Manual Static Analysis: Thoroughly test the comparison scheme before deploying code into production. Perform positive testing as well as negative testing.
Mappings
Related CVEs, CWEs, and ATT&CK context
Related CWEs
ATT&CK Relevance
ATT&CK relevance is shown only when reviewed or responsibly inferred.