Information Exposure Through Discrepancy
|ID: 203||Date: (C)2012-05-14 (M)2020-03-27|
|Type: weakness||Status: INCOMPLETE|
|Abstraction Type: Class|
The product behaves differently or sends different responses in
a way that exposes security-relevant information about the state of the product,
such as whether a particular operation was successful or
Applicable PlatformsLanguage Class: All
Time Of Introduction
- Architecture and Design
|ConfidentialityAccess_Control ||Read application
mechanism ||An attacker can gain access to sensitive information about the system,
including authentication information that may allow an attacker to gain
access to the system. |
|Architecture and Design ||Separation of Privilege ||Compartmentalize the system to have "safe" areas where trust
boundaries can be unambiguously drawn. Do not allow sensitive data to go
outside of the trust boundary and always be careful when interfacing
with a compartment outside of the safe area.Ensure that appropriate compartmentalization is built into the system
design and that the compartmentalization serves to allow for and further
reinforce privilege separation functionality. Architects and designers
should rely on the principle of least privilege to decide when it is
appropriate to use and to drop system privileges. || || |
|Implementation || ||Ensure that error messages only contain minimal details that are
useful to the intended audience, and nobody else. The messages need to
strike the balance between being too cryptic and not being cryptic
enough. They should not necessarily reveal the methods that were used to
determine the error. Such detailed information can be used to refine the
original attack to increase the chances of success.If errors must be tracked in some detail, capture them in log messages
- but consider what could occur if the log messages can be viewed by
attackers. Avoid recording highly sensitive information such as
passwords in any form. Avoid inconsistent messaging that might
accidentally tip off an attacker about internal state, such as whether a
username is valid or not. || || |
|CWE-203 ChildOf CWE-895 ||Category ||CWE-888 || |
Demonstrative Examples (Details)
- The following code checks validity of the supplied username and
password and notifies the user of a successful or failed login. (Demonstrative Example Id DX-38)
- CVE-2002-2094 : This, and others, use ".." attacks and monitor error responses, so there is overlap with directory traversal.
- CVE-2001-1483 : Enumeration of valid usernames based on inconsistent responses
- CVE-2001-1528 : Account number enumeration via inconsistent responses.
- CVE-2004-2150 : User enumeration via discrepancies in error messages.
- CVE-2005-1650 : User enumeration via discrepancies in error messages.
- CVE-2004-0294 : Bulletin Board displays different error messages when a user exists or not, which makes it easier for remote attackers to identify valid users and conduct a brute force password guessing attack.
- CVE-2004-0243 : Operating System, when direct remote login is disabled, displays a different message if the password is correct, which allows remote attackers to guess the password via brute force methods.
- CVE-2002-0514 : Product allows remote attackers to determine if a port is being filtered because the response packet TTL is different than the default TTL.
- CVE-2002-0515 : Product sets a different TTL when a port is being filtered than when it is not being filtered, which allows remote attackers to identify filtered ports by comparing TTLs.
- CVE-2001-1387 : Product may generate different responses than specified by the administrator, possibly leading to an information leak.
- CVE-2004-0778 : Version control system allows remote attackers to determine the existence of arbitrary files and directories via the -X command for an alternate history file, which causes different error messages to be returned.
- CVE-2004-1428 : FTP server generates an error message if the user name does not exist instead of prompting for a password, which allows remote attackers to determine valid usernames.
- CVE-2003-0078 : SSL implementation does not perform a MAC computation if an incorrect block cipher padding is used, which causes an information leak (timing discrepancy) that may make it easier to launch cryptographic attacks that rely on distinguishing between padding and MAC verification errors, possibly leading to extraction of the original plaintext, aka the "Vaudenay timing attack."
- CVE-2000-1117 : Virtual machine allows malicious web site operators to determine the existence of files on the client by measuring delays in the execution of the getSystemResource method.
- CVE-2003-0637 : Product uses a shorter timeout for a non-existent user than a valid user, which makes it easier for remote attackers to guess usernames and conduct brute force password guessing.
- CVE-2003-0190 : Product immediately sends an error message when a user does not exist, which allows remote attackers to determine valid usernames via a timing attack.
- CVE-2004-1602 : FTP server responds in a different amount of time when a given username exists, which allows remote attackers to identify valid usernames by timing the server response.
For more examples, refer to CVE relations in the bottom box.
White Box Definitions None
Black Box Definitions None
|PLOVER || ||Discrepancy Information Leaks || |
|OWASP Top Ten 2007 ||A6 ||Information Leakage and Improper Error
Handling ||CWE_More_Specific |
|OWASP Top Ten 2004 ||A7 ||Improper Error Handling ||CWE_More_Specific |