CWE-204
Observable Response Discrepancy
BaseIncomplete
Description
The product provides different responses to incoming requests in a way that reveals internal state information to an unauthorized actor outside of the intended control sphere.
Hierarchy (View 1000)
Parents
Children
none
Related attack patterns (CAPEC)
CAPEC-331 · CAPEC-332 · CAPEC-541 · CAPEC-580
CVEs mapped to this weakness (38)
page 2 of 2| CVE | Sev | Risk | CVSS | EPSS | KEV | Published | Description |
|---|---|---|---|---|---|---|---|
| CVE-2025-30280 | Med | 0.34 | 5.3 | 0.00 | Apr 8, 2025 | A vulnerability has been identified in Mendix Runtime V10 (All versions < V10.21.0), Mendix Runtime V10.12 (All versions < V10.12.16), Mendix Runtime V10.18 (All versions < V10.18.5), Mendix Runtime V10.6 (All versions < V10.6.22), Mendix Runtime V8 (All versions < V8.18.35), Mendix Runtime V9 (All versions < V9.24.34). Affected applications allow for entity enumeration due to distinguishable responses in certain client actions. This could allow an unauthenticated remote attacker to list all valid entities and attribute names of a Mendix Runtime-based application. | |
| CVE-2025-0693 | Med | 0.34 | 5.3 | 0.00 | Jan 23, 2025 | Variable response times in the AWS Sign-in IAM user login flow allowed for the use of brute force enumeration techniques to identify valid IAM usernames in an arbitrary AWS account. | |
| CVE-2023-49069 | Med | 0.34 | 5.3 | 0.00 | Sep 10, 2024 | A vulnerability has been identified in Mendix Runtime V10 (All versions < V10.17.0 only if the basic authentication mechanism is used by the application), Mendix Runtime V10.12 (All versions < V10.12.11 only if the basic authentication mechanism is used by the application), Mendix Runtime V10.6 (All versions < V10.6.19 only if the basic authentication mechanism is used by the application), Mendix Runtime V8 (All versions < V8.18.33 only if the basic authentication mechanism is used by the application), Mendix Runtime V9 (All versions < V9.24.31 only if the basic authentication mechanism is used by the application). The authentication mechanism of affected applications contains an observable response discrepancy vulnerability when validating usernames. This could allow unauthenticated remote attackers to distinguish between valid and invalid usernames. | |
| CVE-2026-34319 | Med | 0.33 | 5.0 | 0.00 | Apr 21, 2026 | Vulnerability in the MySQL Shell product of Oracle MySQL (component: Shell: Core Client). Supported versions that are affected are 8.0.0-8.0.45, 8.4.0-8.4.8 and 9.0.0-9.6.0. Easily exploitable vulnerability allows low privileged attacker with logon to the infrastructure where MySQL Shell executes to compromise MySQL Shell. Successful attacks require human interaction from a person other than the attacker. Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of MySQL Shell. CVSS 3.1 Base Score 5.0 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H). | |
| CVE-2025-67807 | Med | 0.31 | 4.7 | 0.00 | Apr 1, 2026 | The login mechanism of Sage DPW 2025_06_004 displays distinct responses for valid and invalid usernames, allowing enumeration of existing accounts in versions before 2021_06_000. On-premise administrators can toggle this behaviour in newer versions. | |
| CVE-2025-9824 | Med | 0.31 | 5.9 | 0.00 | Sep 3, 2025 | ImpactThe attacker can validate if a user exists by checking the time login returns. This timing difference can be used to enumerate valid usernames, after which an attacker could attempt brute force attacks. PatchesThis vulnerability has been patched, implementing a timing-safe form login authenticator that ensures consistent response times regardless of whether a user exists or not. Technical DetailsThe vulnerability was caused by different response times when: * A valid username was provided (password hashing occurred) * An invalid username was provided (no password hashing occurred) The fix introduces a TimingSafeFormLoginAuthenticator that performs a dummy password hash verification even for non-existent users, ensuring consistent timing. WorkaroundsNo workarounds are available. Users should upgrade to the patched version. References * https://owasp.org/www-project-web-security-testing-guide/latest/4-Web_Application_Security_Testing/03-Identity_Management_Testing/04-Testing_for_Account_Enumeration_and_Guessable_User_Account | |
| CVE-2024-40627 | Med | 0.31 | 5.8 | 0.00 | Jul 15, 2024 | Fastapi OPA is an opensource fastapi middleware which includes auth flow. HTTP `OPTIONS` requests are always allowed by `OpaMiddleware`, even when they lack authentication, and are passed through directly to the application. `OpaMiddleware` allows all HTTP `OPTIONS` requests without evaluating it against any policy. If an application provides different responses to HTTP `OPTIONS` requests based on an entity existing (such as to indicate whether an entity is writable on a system level), an unauthenticated attacker could discover which entities exist within an application. This issue has been addressed in release version 2.0.1. All users are advised to upgrade. There are no known workarounds for this vulnerability. | |
| CVE-2026-24332 | Med | 0.28 | 4.3 | 0.00 | Jan 22, 2026 | Discord through 2026-01-16 allows gathering information about whether a user's client state is Invisible (and not actually offline) because the response to a WebSocket API request includes the user in the presences array (with "status": "offline"), whereas offline users are omitted from the presences array. This is arguably inconsistent with the UI description of Invisible as "You will appear offline." | |
| CVE-2025-42903 | Med | 0.28 | 4.3 | 0.00 | Oct 14, 2025 | A vulnerability in SAP Financial Service Claims Management RFC function ICL_USER_GET_NAME_AND_ADDRESS allows user enumeration and potential disclosure of personal data through response discrepancies, causing low impact on confidentiality with no impact on integrity or availability. | |
| CVE-2025-58442 | Med | 0.27 | 5.3 | 0.00 | Sep 9, 2025 | Saleor is an e-commerce platform. Starting in version 3.21.0 and prior to version 3.21.16, requesting certain fields in the response of `accountRegister` may result in errors that could unintentionally reveal whether a user with the provided email already exists in Saleor. Version 3.21.16 fixes the issue. As a workaround, rate-limit the mutation to reduce the impact. | |
| CVE-2024-39912 | Med | 0.27 | 5.3 | 0.00 | Jul 15, 2024 | web-auth/webauthn-lib is an open source set of PHP libraries and a Symfony bundle to allow developers to integrate that authentication mechanism into their web applications. The ProfileBasedRequestOptionsBuilder method returns allowedCredentials without any credentials if no username was found. When WebAuthn is used as the first or only authentication method, an attacker can enumerate usernames based on the absence of the `allowedCredentials` property in the assertion options response. This allows enumeration of valid or invalid usernames. By knowing which usernames are valid, attackers can focus their efforts on a smaller set of potential targets, increasing the efficiency and likelihood of successful attacks. This issue has been addressed in version 4.9.0 and all users are advised to upgrade. There are no known workarounds for this vulnerability. | |
| CVE-2026-8242 | Low | 0.24 | 3.7 | 0.00 | May 10, 2026 | A vulnerability was found in Industrial Application Software IAS Canias ERP 8.03. The impacted element is the function doAction of the component Login RMI Interface. Performing a manipulation results in observable response discrepancy. The attack is possible to be carried out remotely. A high degree of complexity is needed for the attack. The exploitability is regarded as difficult. The exploit has been made public and could be used. The vendor was contacted early about this disclosure but did not respond in any way. | |
| CVE-2025-67806 | Low | 0.24 | 3.7 | 0.00 | Apr 1, 2026 | The login mechanism of Sage DPW 2021_06_004 displays distinct responses for valid and invalid usernames, allowing enumeration of existing accounts in versions before 2021_06_000. On-premise administrators can toggle this behavior in newer versions. | |
| CVE-2026-4045 | Low | 0.24 | 3.7 | 0.00 | Mar 12, 2026 | A flaw has been found in projectsend up to r1945. This impacts an unknown function of the file includes/Classes/Auth.php. Executing a manipulation of the argument ldap_email can lead to observable response discrepancy. The attack can be executed remotely. A high complexity level is associated with this attack. The exploitability is said to be difficult. The exploit has been published and may be used. The vendor was contacted early about this disclosure but did not respond in any way. | |
| CVE-2025-9109 | Low | 0.24 | 3.7 | 0.00 | Aug 18, 2025 | A security flaw has been discovered in Portabilis i-Diario up to 1.5.0. Affected by this vulnerability is an unknown functionality of the file /password/email of the component Password Recovery Endpoint. The manipulation results in observable response discrepancy. It is possible to launch the attack remotely. This attack is characterized by high complexity. The exploitation appears to be difficult. The exploit has been released to the public and may be exploited. | |
| CVE-2025-48015 | Low | 0.24 | 3.7 | 0.00 | May 20, 2025 | Failed login response could be different depending on whether the username was local or central. | |
| CVE-2024-12663 | Low | 0.24 | 3.7 | 0.00 | Dec 16, 2024 | A vulnerability classified as problematic was found in funnyzpc Mee-Admin up to 1.6. This vulnerability affects unknown code of the file /mee/login of the component Login. The manipulation of the argument username leads to observable response discrepancy. The attack can be initiated remotely. The complexity of an attack is rather high. The exploitation appears to be difficult. The exploit has been disclosed to the public and may be used. | |
| CVE-2026-39851 | Med | 0.21 | 4.3 | 0.00 | Apr 8, 2026 | Saleor is an e-commerce platform. From 2.10.0 to before 3.23.0a3, 3.22.47, 3.21.54, and 3.20.118, the requestEmailChange() mutation was revealing the existence of user-provided email addresses in error messages. This vulnerability is fixed in 3.23.0a3, 3.22.47, 3.21.54, and 3.20.118. |