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. Because the responses differ in the `error.message`string value, an unauthenticated remote attacker can enumerate valid usernames/accounts on the server. NOTE: D-Link states that a fix is under development.

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 existing account. Because the responses differ in the `data.exist` boolean value, an unauthenticated remote attacker can enumerate valid email addresses/accounts on the server. NOTE: D-Link states that a fix is under development.

Loway - CWE-204: Observable Response Discrepancy

Statamic is a Laravel and Git powered content management system (CMS). Prior to 5.73.21 and 6.15.0, responses from the forgot password forms hinted at whether an account existed for a given email address. An unauthenticated attacker could use this to enumerate valid users, which can aid in follow-up credential-based attacks. This vulnerability is fixed in 5.73.21 and 6.15.0.

ChurchCRM is an open-source church management system. In versions prior to 7.2.0, the public API login endpoint (/api/public/user/login) returns distinguishable HTTP response codes based on whether a username exists: 404 for non-existent users and 401 for valid users with incorrect passwords. An unauthenticated attacker can exploit this difference to enumerate valid usernames, with no rate limiting or account lockout to impede the process. This issue has been fixed in version 7.2.0.

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.

Matrix Tafnit v8 - CWE-204: Observable Response Discrepancy

Kaiten 57.128.8 allows remote attackers to enumerate user accounts via a crafted POST request, because a login response contains a user_email field only if the user account exists.

In Splunk Enterprise versions below 9.2.2, 9.1.5, and 9.0.10 and Splunk Cloud Platform versions below 9.1.2312.109, an attacker could determine whether or not another user exists on the instance by deciphering the error response that they would likely receive from the instance when they attempt to log in. This disclosure could then lead to additional brute-force password-guessing attacks. This vulnerability would require that the Splunk platform instance uses the Security Assertion Markup Language (SAML) authentication scheme.

WWBN AVideo is an open source video platform. In versions up to and including 26.0, the password recovery endpoint at `objects/userRecoverPass.php` performs user existence and account status checks before validating the captcha. This allows an unauthenticated attacker to enumerate valid usernames and determine whether accounts are active, inactive, or banned — at scale and without solving any captcha — by observing three distinct JSON error responses. Commit e42f54123b460fd1b2ee01f2ce3d4a386e88d157 contains a patch.

An observable response discrepancy vulnerability [CWE-204] in FortiClientEMS 7.4.0, 7.2.0 through 7.2.4, 7.0 all versions, and FortiSOAR 7.5.0, 7.4.0 through 7.4.4, 7.3.0 through 7.3.2, 7.2 all versions, 7.0 all versions, 6.4 all versions may allow an unauthenticated attacker to enumerate valid users via observing login request responses.

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.51 and 9.6.0-alpha.40, the Pages route and legacy PublicAPI route for resending email verification links return distinguishable responses depending on whether the provided username exists and has an unverified email. This allows an unauthenticated attacker to enumerate valid usernames by observing different redirect targets. The existing emailVerifySuccessOnInvalidEmail configuration option, which is enabled by default and protects the API route against this, did not apply to these routes. This issue has been patched in versions 8.6.51 and 9.6.0-alpha.40.

IBM Control Center 6.2.1 and 6.3.1 could allow a remote attacker to enumerate usernames due to an observable discrepancy between login attempts.

An issue was discovered in Logpoint before 7.4.0. An attacker can enumerate a valid list of usernames by observing the response time at the Forgot Password endpoint.

User enumeration vulnerability in ORDAT FOSS-Online before v2.24.01 allows attackers to determine if an account exists in the application by comparing the server responses of the forgot password functionality.

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.

Liferay Portal 7.2.0 through 7.4.1, and older unsupported versions, and Liferay DXP 7.3 before service pack 3, 7.2 before fix pack 18, and older unsupported versions returns with different responses depending on whether a site does not exist or if the user does not have permission to access the site, which allows remote attackers to discover the existence of sites by enumerating URLs. This vulnerability occurs if locale.prepend.friendly.url.style=2 and if a custom 404 page is used.

Observable Response Discrepancy in GitHub repository answerdev/answer prior to 1.0.6.

Umbraco is an ASP.NET content management system. Umbraco 10 prior to 10.8.4 with access to the native login screen is vulnerable to a possible user enumeration attack. This issue was fixed in version 10.8.5. As a workaround, one may disable the native login screen by exclusively using external logins.

A user enumeration vulnerability exists in the login functionality of Ghost Foundation Ghost 5.9.4. A specially-crafted HTTP request can lead to a disclosure of sensitive information. An attacker can send a series of HTTP requests to trigger this vulnerability.

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 4.10.11; Niagara Enterprise Security: before 4.14.2, before 4.15.1, before 4.10.11.Tridium recommends upgrading to Niagara Framework and Enterprise Security versions 4.14.2u2, 4.15.u1, or 4.10u.11.

The check user account lock states feature within the email OTP flow fails to validate user input, allowing an attacker to infer the existence of registered user accounts. The discovery of valid usernames can increase the risk of brute-force and social engineering attacks. Attackers can leverage this information to craft targeted phishing campaigns or other malicious activities aimed at tricking users into divulging sensitive data, potentially damaging the organization's reputation and leading to regulatory non-compliance and financial consequences.

Kirby is a Content Management System. Prior to versions 3.5.8.2, 3.6.6.2, 3.7.5.1, and 3.8.1, a user enumeration vulnerability affects all Kirby sites with user accounts unless Kirby's API and Panel are disabled in the config. It can only be exploited for targeted attacks because the attack does not scale to brute force. The problem has been patched in Kirby 3.5.8.2, Kirby 3.6.6.2, Kirby 3.7.5.1, and Kirby 3.8.1. In all of the mentioned releases, the maintainers have rewritten the affected code so that the delay is also inserted after the brute force limit is reached.

vantage6 is a privacy preserving federated learning infrastructure for secure insight exchange. vantage6 does not inform the user of wrong username/password combination if the username actually exists. This is an attempt to prevent bots from obtaining usernames. However, if a wrong password is entered a number of times, the user account is blocked temporarily. This issue has been fixed in version 3.8.0.

User enumeration vulnerability in Devklan's Alma Blog that affects versions 2.1.10 and earlier. This vulnerability could allow a remote user to retrieve all valid users registered in the application just by looking at the request response.

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 if the user doesn't exist and report "Username or Password invalid". While the setting was correctly respected during the login flow, the user's username was normalized leading to a disclosure of the user's existence. This vulnerability is fixed in 2.71.6, 2.70.8, 2.69.9, 2.68.9, 2.67.13, 2.66.16, 2.65.7, 2.64.6, and 2.63.9.

IBM Aspera Orchestrator 4.0.1 could allow a remote attacker to enumerate usernames due to observable response discrepancies. IBM X-Force ID: 248545.

A vulnerability in the login functionality of the web application of ctrlX OS allows a remote unauthenticated attacker to guess valid usernames via multiple crafted HTTP requests.

Accellion FTP server prior to version FTA_9_12_220 only returns the username in the server response if the username is invalid. An attacker may use this information to determine valid user accounts and enumerate them.

User enumeration vulnerability in Arconte Áurea 1.5.0.0 version. The exploitation of this vulnerability could allow an attacker to obtain a list of registered users in the application, obtaining the necessary information to perform more complex attacks on the platform.

A remote, unauthenticated attacker can enumerate valid users by sending specific requests to the webservice of MB connect line mymbCONNECT24, mbCONNECT24 and Helmholz myREX24 and myREX24.virtual in all versions through v2.11.2.