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.
View on MITREAn 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.
No mitigation information available for this CWE.
Thoroughly test the comparison scheme before deploying code into production. Perform positive testing as well as negative testing.
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.
public class Truck { private String make;private String model;private int year; public boolean equals(Object o) { if (o == null) return false;if (o == this) return true;if (!(o instanceof Truck)) return false; Truck t = (Truck) o; return (this.make.equals(t.getMake()) && this.model.equals(t.getModel())); } }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.
/* Ignore CWE-259 (hard-coded password) and CWE-309 (use of password system for authentication) for this example. */ char *username = "admin";char *pass = "password"; int AuthenticateUser(char *inUser, char *inPass) {if (strncmp(username, inUser, strlen(inUser))) {logEvent("Auth failure of username using strlen of inUser");return(AUTH_FAIL);}if (! strncmp(pass, inPass, strlen(inPass))) {logEvent("Auth success of password using strlen of inUser");return(AUTH_SUCCESS);}else {logEvent("Auth fail of password using sizeof");return(AUTH_FAIL);}} int main (int argc, char **argv) { int authResult;if (argc < 3) {ExitError("Usage: Provide a username and password");}authResult = AuthenticateUser(argv[1], argv[2]);if (authResult == AUTH_SUCCESS) {DoAuthenticatedTask(argv[1]);}else {ExitError("Authentication failed");}}PHP remote file inclusion in web application that filters "http" and "https" URLs, but not "ftp".
View DetailsProduct does not prevent access to restricted directories due to partial string comparison with a public directory
View DetailsAdditional facts reviewed against primary or authoritative security sources.
Documented detection approaches include Manual Static Analysis; recorded impacts include Alter Execution Logic, and Bypass Protection Mechanism; observed examples include CVE-2005-2782, and CVE-2014-6394. Use these source-defined anchors to turn CWE-1023 into implementation, review, and verification checks for the affected component.
CWE-1023: Incomplete Comparison with Missing Factors — MITRE CWEUse NIST SSDF practices to make prevention of CWE-1023, Incomplete Comparison with Missing Factors, an explicit development outcome. Translate the CWE definition into security requirements and design constraints, choose safer implementation patterns and toolchain checks, and define acceptance evidence before release. Feed every confirmed occurrence back into the requirements, design review, and coding rules so the same root cause is removed across the product rather than patched in one location.
NIST SP 800-218 Secure Software Development Framework — National Institute of Standards and TechnologyUse CISA's Known Exploited Vulnerabilities catalog to test whether a vulnerability mapped to CWE-1023, Incomplete Comparison with Missing Factors, has evidence of exploitation in the wild. Confirm the CVE-to-CWE root-cause mapping independently before attaching the example, then capture the affected product, required action, and remediation deadline. A missing KEV match is not evidence that the weakness is unexploited, and a KEV entry must not be generalized to every occurrence of this CWE.
Known Exploited Vulnerabilities Catalog — Cybersecurity and Infrastructure Security AgencyApply MITRE's full root-cause mapping guidance when using CWE-1023, Incomplete Comparison with Missing Factors. Separate weakness language from attacker prerequisites and technical impact, check the entry's abstraction and vulnerability-mapping notes, and prefer the most specific Base or Variant supported by the evidence. Record the rejected alternatives and require an independent review before the mapping is used for remediation trends or program metrics.
CVE to CWE Root Cause Mapping Guidance — MITRE CWEApply MITRE's root-cause mapping quick tips to CWE-1023, Incomplete Comparison with Missing Factors. Confirm the finding describes the causal weakness rather than an impact or attack pattern, compare the abstraction and mapping notes with plausible alternatives, and have a second reviewer challenge the selection. Preserve the evidence and reasoning so recurring defects can be measured against one consistent identifier.
CVE to CWE Root Cause Mapping Quick Tips — MITRE CWECWE-1023: Incomplete Comparison with Missing Factors is a Common Weakness Enumeration (CWE) entry maintained by MITRE. 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.
If exploited, CWE-1023 (Incomplete Comparison with Missing Factors) it can compromise Integrity and Access Control, leading to outcomes such as Alter Execution Logic and Bypass Protection Mechanism.
CWE-1023 can be detected using Manual Static Analysis. Combining automated tooling with manual review typically yields the best coverage.
CWE-1023 commonly affects Not Language-Specific. Note that weaknesses are often language-agnostic patterns, so secure coding practices apply broadly.
MITRE documents real CVEs mapped to CWE-1023, including CVE-2005-2782 and CVE-2014-6394. You can look up the full details of each CVE, including CVSS scores and remediation guidance, on our CVE Lookup tool.
A CWE (Common Weakness Enumeration) like CWE-1023 describes a category of software weakness — the underlying flaw type. A CVE (Common Vulnerabilities and Exposures) identifies a specific, real-world vulnerability in a particular product. In short, a CWE is the kind of mistake, and a CVE is an instance of that mistake being found in software.