CWE-203: Observable Discrepancy
CWE版本: 4.18
更新日期: 2025-09-09
弱点描述
The product behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor, which exposes security-relevant information about the state of the product, such as whether a particular operation was successful or not.
扩展描述
Discrepancies can take many forms, and variations may be detectable in timing, control flow, communications such as replies or requests, or general behavior. These discrepancies can reveal information about the product's operation or internal state to an unauthorized actor. In some cases, discrepancies can be used by attackers to form a side channel.
常见后果
影响范围: Confidentiality Access Control
技术影响: Read Application Data Bypass Protection Mechanism
说明: 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.
影响范围: Confidentiality
技术影响: Read Application Data
说明: When cryptographic primitives are vulnerable to side-channel-attacks, this could be used to reveal unencrypted plaintext in the worst case.
潜在缓解措施
阶段: Architecture and Design
策略: Separation of Privilege
阶段: Implementation
观察示例
参考: CVE-2020-8695
Observable discrepancy in the RAPL interface for some Intel processors allows information disclosure.
参考: CVE-2019-14353
Crypto hardware wallet's power consumption relates to total number of pixels illuminated, creating a side channel in the USB connection that allows attackers to determine secrets displayed such as PIN numbers and passwords
参考: CVE-2019-10071
Java-oriented framework compares HMAC signatures using String.equals() instead of a constant-time algorithm, causing timing discrepancies
参考: CVE-2002-2094
This, and others, use ".." attacks and monitor error responses, so there is overlap with directory traversal.
参考: CVE-2001-1483
Enumeration of valid usernames based on inconsistent responses
参考: CVE-2001-1528
Account number enumeration via inconsistent responses.
参考: CVE-2004-2150
User enumeration via discrepancies in error messages.
参考: CVE-2005-1650
User enumeration via discrepancies in error messages.
参考: 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.
参考: 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.
参考: 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.
参考: 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.
参考: CVE-2002-0208
Product modifies TCP/IP stack and ICMP error messages in unusual ways that show the product is in use.
参考: CVE-2004-2252
Behavioral infoleak by responding to SYN-FIN packets.
参考: CVE-2001-1387
Product may generate different responses than specified by the administrator, possibly leading to an information leak.
参考: 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.
参考: 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.
参考: 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."
参考: 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.
参考: 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.
参考: 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.
参考: 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.
参考: CVE-2005-0918
Browser allows remote attackers to determine the existence of arbitrary files by setting the src property to the target filename and using Javascript to determine if the web page immediately stops loading, which indicates whether the file exists or not.
引入模式
| 阶段 | 说明 |
|---|---|
| Architecture and Design | - |
| Implementation | - |
适用平台
编程语言
技术
分类映射
| 分类名称 | 条目ID | 条目名称 | 映射适配度 |
|---|---|---|---|
| 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 |