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.
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.
Threat Mapped score: 0.0
Industry: Finiancial
Threat priority: Unclassified
CVE: CVE-2005-2782
PHP remote file inclusion in web application that filters "http" and "https" URLs, but not "ftp".
CVE: CVE-2014-6394
Product does not prevent access to restricted directories due to partial string comparison with a public directory
N/A
N/A
| Phase | Note |
|---|---|
| Implementation | N/A |
Intro: 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.
Body: 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())); } }Intro: 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.
Body: 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"); } }