The open-source identity infrastructure software Zitadel allows administrators to disable the user self-registration. Versions 4.0.0 to 4.0.2, 3.0.0 to 3.3.6, and all versions prior to 2.71.15 are vulnerable to a username enumeration issue in the login interface. The login UI includes a security feature, Ignoring unknown usernames, that is intended to prevent username enumeration by returning a generic response for both valid and invalid usernames. This vulnerability allows an unauthenticated attacker to bypass this protection by submitting arbitrary userIDs to the select account page and distinguishing between valid and invalid accounts based on the system's response. For effective exploitation, an attacker needs to iterate through possible userIDs, but the impact can be limited by implementing rate limiting or similar measures. The issue has been patched in versions 4.0.3, 3.4.0, and 2.71.15.

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.

Zitadel is an open source identity management system. In case ZITADEL could not connect to the database, connection information including db name, username and db host name could be returned to the user. This has been addressed in all supported release branches in a point release. There is no workaround since a patch is already available. Users are advised to upgrade.

ZITADEL provides identity infrastructure. In versions 2.37.2 and prior, ZITADEL administrators can enable a setting called "Ignoring unknown usernames" which helps mitigate attacks that try to guess/enumerate usernames. While this settings was properly working during the authentication process it did not work correctly on the password reset flow. This meant that even if this feature was active that an attacker could use the password reset function to verify if an account exist within ZITADEL. This bug has been patched in versions 2.37.3 and 2.38.0. No known workarounds are available.

Dalmark Systems Systeam 2.22.8 build 1724 is vulnerable to User enumeration. The Systeam application is an ERP system that uses a mixed architecture based on SaaS tenant and user management, and on-premise database and web application counterparts. This issue occurs during the identification of the correct tenant for a given user, where a difference in messages could allow an attacker to determine if the given user is valid or not, enabling a brute force attack with valid users.

In Cibele Thinfinity VirtualUI before 3.0, /changePassword returns different responses for invalid authentication requests depending on whether the username exists.

UrBackup Server 2.5.31 allows brute-force enumeration of user accounts because a failure message confirms that a username is not valid.

Observable discrepancies in the login process allow an attacker to guess legitimate user names registered in the BMC. This issue affects: Lanner Inc IAC-AST2500A standard firmware version 1.10.0.

Thinfinity VirtualUI before 3.0 allows a malicious actor to enumerate users registered in the OS (Windows) through the /changePassword URI. By accessing the vector, an attacker can determine if a username exists thanks to the message returned; it can be presented in different languages according to the configuration of VirtualUI. Common users are administrator, admin, guest and krgtbt.

Crypto++ (aka Cryptopp) 8.6.0 and earlier contains a timing leakage in MakePublicKey(). There is a clear correlation between execution time and private key length, which may cause disclosure of the length information of the private key. This might allow attackers to conduct timing attacks. NOTE: this report is disputed by the vendor and multiple third parties. The execution-time differences are intentional. A user may make a choice of a longer key as a tradeoff between strength and performance. In making this choice, the amount of information leaked to an adversary is of infinitesimal value

An issue was discovered in Django v5.1.1, v5.0.9, and v4.2.16. The django.contrib.auth.forms.PasswordResetForm class, when used in a view implementing password reset flows, allows remote attackers to enumerate user e-mail addresses by sending password reset requests and observing the outcome (only when e-mail sending is consistently failing).

A user enumeration vulnerability in MELAG FTP Server 2.2.0.4 allows an attacker to identify valid FTP usernames.

A user enumeration vulnerability flaw was found in Venki Supravizio BPM 10.1.2. This issue occurs during password recovery, where a difference in error messages could allow an attacker to determine if a username is valid or not, enabling a brute-force attack with valid usernames.

webcalendar before 1.2.7 shows the reason for a failed login (e.g., "no such user").

The password-reset form in ServiceNow Orlando provides different responses to invalid authentication attempts depending on whether the username exists.

Loway - CWE-204: Observable Response Discrepancy

Pimcore is an open source data & experience management platform. In versions prior to 10.1.3, it is possible to enumerate usernames via the forgot password functionality. This issue is fixed in version 10.1.3. As a workaround, one may apply the available patch manually.

In veilid-core in Veilid before 0.3.4, the protocol's ping function can be misused in a way that decreases the effectiveness of safety and private routes.

In the Twilio Authy API, accessed by Authy Android before 25.1.0 and Authy iOS before 26.1.0, an unauthenticated endpoint provided access to certain phone-number data, as exploited in the wild in June 2024. Specifically, the endpoint accepted a stream of requests containing phone numbers, and responded with information about whether each phone number was registered with Authy. (Authy accounts were not compromised, however.)

Accounts enumeration vulnerability in the Login Component of Reolink Duo 2 WiFi Camera (Firmware Version v3.0.0.1889_23031701) allows remote attackers to determine valid user accounts via login attempts. This can lead to the enumeration of user accounts and potentially facilitate other attacks, such as brute-forcing of passwords. The vulnerability arises from the application responding differently to login attempts with valid and invalid usernames.

Matrix Tafnit v8 - CWE-204: Observable Response Discrepancy

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.

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.

Dalmark Systems Systeam 2.22.8 build 1724 is vulnerable to User enumeration. The Systeam application is an ERP system that uses a mixed architecture based on SaaS tenant and user management, and on-premise database and web application counterparts. This issue occurs during the password recovery procedure for a given user, where a difference in messages could allow an attacker to determine if the given user is valid or not, enabling a brute force attack with valid users.

Observable behavioral discrepancy vulnerability in QSAN Storage Manager allows remote attackers to obtain the system information without permissions. Suggest contacting with QSAN and refer to recommendations in QSAN Document.

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.

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.

IBM Security Identity Manager 7.0.2 could allow a remote user to enumerate usernames due to a difference of responses from valid and invalid login attempts. IBM X-Force ID: 200018

Flask-AppBuilder is a development framework, built on top of Flask. User enumeration in database authentication in Flask-AppBuilder <= 3.2.3. Allows for a non authenticated user to enumerate existing accounts by timing the response time from the server when you are logging in. Upgrade to version 3.3.0 or higher to resolve.

IBM i 7.2, 7.3, 7.4, and 7.5 Service Tools Server (SST) is vulnerable to SST user enumeration by a remote attacker. This vulnerability can be used by a malicious actor to gather information about SST users that can be targeted in further attacks. IBM X-Force ID: 287538.

In Directus 8.x through 8.8.1, an attacker can discover whether a user is present in the database through the password reset feature. NOTE: This vulnerability only affects products that are no longer supported by the maintainer

In Logpoint before 7.4.0, an attacker can enumerate a valid list of usernames by using publicly exposed URLs of shared widgets.

User enumeration vulnerability in Liferay Portal 7.2.0 through 7.4.3.26, and older unsupported versions, and Liferay DXP 7.4 before update 27, 7.3 before update 8, 7.2 before fix pack 20, and older unsupported versions allows remote attackers to determine if an account exist in the application by comparing the request's response time.

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.

User enumeration can occur in the Authentication REST API in Delinea PAM Secret Server 11.4. This allows a remote attacker to determine whether a user is valid because of a difference in responses from the /oauth2/token endpoint.

An user enumeration vulnerability was found in SEO Panel 4.10.0. This issue occurs during user authentication, where a difference in error messages could allow an attacker to determine if a username is valid or not, enabling a brute-force attack with valid usernames.

A vulnerability has been identified in Mendix Forgot Password (Mendix 10 compatible) (All versions < V5.4.0), Mendix Forgot Password (Mendix 7 compatible) (All versions < V3.7.3), Mendix Forgot Password (Mendix 8 compatible) (All versions < V4.1.3), Mendix Forgot Password (Mendix 9 compatible) (All versions < V5.4.0). Applications using the affected module are vulnerable to user enumeration due to distinguishable responses. This could allow an unauthenticated remote attacker to determine if a user is valid or not, enabling a brute force attack with valid users.

Fides is an open-source privacy engineering platform. Prior to version 2.44.0, a timing-based username enumeration vulnerability exists in Fides Webserver authentication. This vulnerability allows an unauthenticated attacker to determine the existence of valid usernames by analyzing the time it takes for the server to respond to login requests. The discrepancy in response times between valid and invalid usernames can be leveraged to enumerate users on the system. This vulnerability enables a timing-based username enumeration attack. An attacker can systematically guess and verify which usernames are valid by measuring the server's response time to authentication requests. This information can be used to conduct further attacks on authentication such as password brute-forcing and credential stuffing. The vulnerability has been patched in Fides version `2.44.0`. Users are advised to upgrade to this version or later to secure their systems against this threat. There are no workarounds.

LabVantage LIMS 8.3 does not properly maintain the confidentiality of database names. For example, the web application exposes the database name. An attacker might be able to enumerate database names by providing his own database name in a request, because the response will return an 'Unrecognized Database exception message if the database does not exist.

Piccolo is an ORM and query builder which supports asyncio. In versions 0.120.0 and prior, the implementation of `BaseUser.login` leaks enough information to a malicious user such that they would be able to successfully generate a list of valid users on the platform. As Piccolo on its own does not also enforce strong passwords, these lists of valid accounts are likely to be used in a password spray attack with the outcome being attempted takeover of user accounts on the platform. The impact of this vulnerability is minor as it requires chaining with other attack vectors in order to gain more then simply a list of valid users on the underlying platform. The likelihood of this vulnerability is possible as it requires minimal skills to pull off, especially given the underlying login functionality for Piccolo based sites is open source. This issue has been patched in version 0.121.0.

IBM TXSeries for Multiplatforms 10.1 could allow an attacker to determine valid usernames due to an observable timing discrepancy which could be used in further attacks against the system.

In Bromite through 78.0.3904.130, there are adblock rules in the release APK; therefore, probing which resources are blocked and which aren't can identify the application version and defeat the User-Agent protection mechanism.

_account_forgot_password.ajax.php in MFScripts YetiShare 3.5.2 through 4.5.3 takes a different amount of time to return depending on whether an email address is configured for the account name provided. This can be used by an attacker to enumerate accounts by guessing email addresses.

Using iterative requests an attacker was able to learn the size of an opaque response, as well as the contents of a server-supplied Vary header. This vulnerability affects Firefox < 119.

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.

An issue was discovered in Symfony 4.2.0 to 4.2.11 and 4.3.0 to 4.3.7. The ability to enumerate users was possible due to different handling depending on whether the user existed when making unauthorized attempts to use the switch users functionality. This is related to symfony/security.

goauthentik is an open-source Identity Provider. In affected versions using a recovery flow with an identification stage an attacker is able to determine if a username exists. Only setups configured with a recovery flow are impacted by this. Anyone with a user account on a system with the recovery flow described above is susceptible to having their username/email revealed as existing. An attacker can easily enumerate and check users' existence using the recovery flow, as a clear message is shown when a user doesn't exist. Depending on configuration this can either be done by username, email, or both. This issue has been addressed in versions 2023.5.6 and 2023.6.2. Users are advised to upgrade. There are no known workarounds for this issue.

The commit 3730880 (April 2023) and v.0.9-beta1 of gugoan Economizzer has a user enumeration vulnerability in the login and forgot password functionalities. The app reacts differently when a user or email address is valid, and when it's not. This may allow an attacker to determine whether a user or email address is valid, or brute force valid usernames and email addresses.

An issue was discovered in eGroupWare 17.1.20190111. A User Enumeration vulnerability exists under calendar/freebusy.php, which allows unauthenticated remote attackers to enumerate the users of web applications based on server response.