Weakness (CWE)
CWE-204: Observable Response Discrepancy
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.
How to prevent it (2 mitigations)
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Architecture and Design
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 the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.
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Implementation
Ensure that error messages only contain minimal details that are useful to the intended audience and no one else. The messages need to strike the balance between being too cryptic (which can confuse users) or being too detailed (which may reveal more than intended). The messages should not reveal the methods that were used to determine the error. Attackers can use detailed information to refine or optimize their original attack, thereby increasing their chances of success.
If errors must be captured in some detail, record them in log messages, but consider what could occur if the log messages can be viewed by attackers. Highly sensitive information such as passwords should never be saved to log files.
Avoid inconsistent messaging that might accidentally tip off an attacker about internal state, such as whether a user account exists or not.
Source: MITRE CWE-204
182 results · Clear filters · Feed
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Medium 5.3
Gitea's /api/v1/user endpoint has different responses for failed authentication depending on whether a username exists
In Gitea before 1.25.2, /api/v1/user has different responses for failed authentication depending on whether a username exists.
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Medium 6.9
ChurchCRM has plaintext password return in response
ChurchCRM is an open-source church management system. Prior to version 6.5.0, the application echoes back plaintext passwords submitted by users in subsequent HTTP responses. This information disclosure significantly increases the risk of credential compromis…
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Medium 5.3
Pega Platform versions 7.1.0 through Infinity 25.1.0 are affected by a User Enumeration where during user authentication process, a difference in response time could allow a remote unauthenticated user to determine if a username is valid or not.
Pega Platform versions 7.1.0 through Infinity 25.1.0 are affected by a User Enumeration. This issue occurs during user authentication process, where a difference in response time could allow a remote unauthenticated user to determine if a username is valid or…
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Medium 6.9
IntelliChoice eFORCE Software Suite Username Enumeration
IntelliChoice eFORCE Software Suite 2.5.9 contains a username enumeration vulnerability that allows attackers to enumerate valid users by exploiting the 'ctl00$MainContent$UserName' POST parameter. Attackers can send requests with valid usernames to retrieve …
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Medium 5.3
A vulnerability has been identified in Gridscale X Prepay (All versions < V4.2.1). The affected application is vulnerab…
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Medium 5.3
Medtronic CareLink Network allows an unauthenticated remote attacker to initiate a request for security questions to an…
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Medium 5.3CVE-2025-65899 Public exploit
Kalmia CMS version 0.2.0 contains a user enumeration vulnerability in its authentication mechanism. The application ret…
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Medium 6.5
Grav Admin Plugin vulnerable to User Enumeration & Email Disclosure
This admin plugin for Grav is an HTML user interface that provides a convenient way to configure Grav and easily create and modify pages. Prior to 1.11.0-beta.1, a user enumeration and email disclosure vulnerability exists in Grav. The "Forgot Password" funct…
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Medium 6.9
User enumeration in Windu CMS
Windu CMS is vulnerable to User Enumeration. This issue occurs during logon, where a difference in messages could allow an attacker to determine if the login is valid or not, enabling a brute force attack with valid logins. Only version 4.1 was tested and con…
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Medium 5.3
Omnissa Workspace ONE UEM contains an observable response discrepancy vulnerability. A malicious actor may be able to e…
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Medium 5.3
Frontier Airlines publicly available email address validation
The Frontier Airlines website has a publicly available endpoint that validates if an email addresses is associated with an account. An unauthenticated, remote attacker could determine valid email addresses, possibly aiding in further attacks.
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Medium 6.9
Tibbo AggreGate Network Manager < 6.40.05 Login Functionality User Enumeration
Tibbo AggreGate Network Manager < 6.40.05 contains an observable response discrepancy in its login functionality. Authentication failure messages differ based on whether a supplied username exists or not, allowing an unauthenticated remote attacker to infer v…
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Medium 6.9
D-Link Nuclias Connect <= v1.3.1.4 Forgot Password Account Enumeration
D-Link Nuclias Connect firmware versions <= 1.3.1.4 contain an observable response discrepancy vulnerability. The application's 'Forgot Password' endpoint returns distinct JSON responses depending on whether the supplied email address is associated with an ex…
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Medium 6.9
D-Link Nuclias Connect <= v1.3.1.4 Login Account Enumeration
D-Link Nuclias Connect firmware versions <= 1.3.1.4 contain an observable response discrepancy vulnerability. The application's 'Login' endpoint returns distinct JSON responses depending on whether the supplied username is associated with an existing account.…
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Medium 5.3
Icinga DB Web hidden/protected custom variables are prone to filter enumeration
Icinga DB Web provides a graphical interface for Icinga monitoring. Before 1.1.4 and 1.2.3, an authorized user with access to Icinga DB Web, can use a custom variable in a filter that is either protected by icingadb/protect/variables or hidden by icingadb/den…
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Medium 4.3
User Enumeration and Sensitive Data Exposure via RFC Function in SAP Financial Service Claims Management
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 int…
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Medium 5.3
User Enumeration by excessive error output
For failed login attempts, the application returns different error messages depending on whether the login failed due to an incorrect password or a non-existing username. This allows an attacker to guess usernames until they find an existing one.
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Medium 5.3CVE-2025-56764 Public exploit
Trivision NC-227WF firmware 5.80 (build 20141010) login mechanism reveals whether a username exists or not by returning…
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Medium 5.3
Saleor has user enumeration vulnerability due to different error messages
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 exi…
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Medium 5.9
User Enumeration via Response Timing
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, implem…
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Medium 6.5CVE-2025-46047 Public exploit
Silverpeas Core Username Enumeration Vulnerability
A User enumeration vulnerability in the /CredentialsServlet/ForgotPassword endpoint in Silverpeas 6.4.1 and 6.4.2 allows remote attackers to determine valid usernames via the Login parameter.
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Medium 5.3
OPEXUS FOIAXpress Public Access Link (PAL) unauthenticated username enumeration
OPEXUS FOIAXpress Public Access Link (PAL) version v11.1.0 allows an unauthenticated, remote attacker to query the /App/CreateRequest.aspx endpoint to check for the existence of valid usernames. There are no rate-limiting mechanisms in place.
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Medium 5.3
Tuleap vulnerable to user enumeration via the lost password form
Tuleap is an Open Source Suite created to facilitate management of software development and collaboration. In Tuleap Community Edition prior to version 16.9.99.1750843170 and Tuleap Enterprise Edition prior to 16.8-4 and 16.9-2, the forgot password form allow…
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Medium 4.3
HAXiam allows for User Enumeration
HAXiam is a packaging wrapper for HAXcms which allows anyone to spawn their own microsite management platform. In versions 11.0.4 and below, the application returns a 200 response when requesting the data of a valid user and a 404 response when requesting the…
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Medium 5.3
CVE-2025-27451
For failed login attempts, the application returns different error messages depending on whether the login failed due to an incorrect password or a non-existing username. This allows an attacker to guess usernames until they find an existing one.
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Medium 5.3
User enumeration
For failed login attempts, the application returns different error messages depending on whether the login failed due to an incorrect password or a non-existing username. This allows an attacker to guess usernames until they find an existing one.
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Medium 5.3
IBM Security Verify Access information disclosure
IBM Security Verify Access Appliance and Docker 10.0 through 10.0.8 could allow a remote attacker to enumerate usernames due to an observable response discrepancy of disabled accounts.
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Medium 5.3
User name enumeration possible due to response time difference on password reset form
SummaryThis advisory addresses a security vulnerability in Mautic related to the "Forget your password" functionality. This vulnerability could be exploited by unauthenticated users to enumerate valid usernames. User Enumeration via Timing Attack: A user enum…
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Medium 5.3
Observable Response Discrepancy
Observable Response Discrepancy vulnerability in Tridium Niagara Framework on Windows, Linux, QNX, Tridium Niagara Enterprise Security on Windows, Linux, QNX allows Cryptanalysis. This issue affects Niagara Framework: before 4.14.2, before 4.15.1, before 4.10…
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Medium 5.3
A vulnerability has been identified in Polarion V2310 (All versions), Polarion V2404 (All versions < V2404.2). The logi…
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Medium 5.3
Umbraco Makes User Enumeration Feasible Based on Timing of Login Response
Umbraco is a free and open source .NET content management system. Prior to versions 10.8.10 and 13.8.1, based on an analysis of the timing of post login API responses, it's possible to determine whether an account exists. The issue is patched in versions 10.8…
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Medium 5.3
A vulnerability in the login functionality of the web application of ctrlX OS allows a remote unauthenticated attacker …
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Medium 5.3
Silverstripe Framework user enumeration via timing attack on login and password reset forms
### Impact User enumeration is possible by performing a timing attack on the login or password reset pages with user credentials. This was originally disclosed in https://www.silverstripe.org/download/security-releases/ss-2017-005/ for CMS 3 but was not patch…
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Medium 5.5
Shopware 6 allows attackers to check for registered accounts through the store-api
Shopware 6 is an open commerce platform based on Symfony Framework and Vue. Through the store-api it is possible as a attacker to check if a specific e-mail address has an account in the shop. Using the store-api endpoint /store-api/account/recovery-password …
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Medium 5.3
A vulnerability has been identified in Mendix Runtime V10 (All versions < V10.21.0), Mendix Runtime V10.12 (All version…
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Medium 5.3
IBM TXSeries for Multiplatforms information disclosure
IBM TXSeries for Multiplatforms 9.1 and 11.1 could allow an attacker to enumerate usernames due to an observable login attempt response discrepancy.
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Medium 5.3
Zitadel allows User Enumeration by loginname attribute normalization
Zitadel is open-source identity infrastructure software. ZITADEL administrators can enable a setting called "Ignoring unknown usernames" which helps mitigate attacks that try to guess/enumerate usernames. If enabled, ZITADEL will show the password prompt even…
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Medium 6.9
User enumeration vulnerability in MeetMe products
User enumeration in the password reset module of the MeetMe authentication service in versions prior to 2024-09 allows an attacker to determine whether an email address is registered through specific error messages.
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Medium 5.3
User Enumeration via Discrepancies in Error Messages in the Celk Sistemas Celk Saude v.3.1.252.1 password recovery func…
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Medium 5.3
A CWE-204 "Observable Response Discrepancy" in the login page in Q-Free MaxTime less than or equal to version 2.11.0 al…