A vulnerability in the External Interface of OTRS allows conclusions to be drawn about the existence of user accounts through different HTTP response codes and messages. This enables an attacker to systematically identify valid email addresses. This issue affects: * OTRS 7.0.X * OTRS 8.0.X * OTRS 2023.X * OTRS 2024.X * OTRS 2025.X

Umbraco is a free and open source .NET content management system. Starting in version 14.0.0 and prior to versions 14.3.2 and 15.1.2, it's possible to determine whether an account exists based on an analysis of response codes and timing of Umbraco management API responses. Versions 14.3.2 and 15.1.2 contain a patch. No known workarounds are available.

A username enumeration vulnerability exists in multiple WSO2 products when Multi-Attribute Login is enabled. In this configuration, the system returns a distinct "User does not exist" error message to the login form, regardless of the validate_username setting. This behavior allows malicious actors to determine which usernames exist in the system based on observable discrepancies in the application's responses. Exploitation of this vulnerability could aid in brute-force attacks, targeted phishing campaigns, or other social engineering techniques by confirming the validity of user identifiers within the system.

By checking the result of calls to `window.open` with specifically set protocol handlers, an attacker could determine if the application which implements that protocol handler is installed. This vulnerability affects Firefox < 131, Firefox ESR < 128.3, Thunderbird < 128.3, and Thunderbird < 131.

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.

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.

Username enumeration is possible through Bypassing CAPTCHA in On-premise SureMDM Solution on Windows deployment allows attacker to enumerate local user information via error message. This issue affects SureMDM On-premise: 6.31 and below version

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.

The login functionality of the web server in affected devices does not normalize the response times of login attempts. An unauthenticated remote attacker could exploit this side-channel information to distinguish between valid and invalid usernames.

IBM Aspera Faspex 5.0.0 through 5.0.10 could disclose sensitive username information due to an observable response discrepancy.

Tadiran Telecom Aeonix - CWE-204: Observable Response Discrepancy

Observable Response Discrepancy in the SICK ICR890-4 could allow a remote attacker to identify valid usernames for the FTP server from the response given during a failed login attempt.

A vulnerability classified as problematic has been found in Rotem Dynamics Rotem CRM up to 20230729. This affects an unknown part of the file /LandingPages/api/otp/send?id=[ID][ampersand]method=sms of the component OTP URI Interface. The manipulation leads to information exposure through discrepancy. It is possible to initiate the attack remotely. The identifier VDB-233253 was assigned to this vulnerability. NOTE: The vendor was contacted early about this disclosure but did not respond in any way.

HashiCorp's Vault and Vault Enterprise are vulnerable to user enumeration when using the LDAP auth method. An attacker may submit requests of existent and non-existent LDAP users and observe the response from Vault to check if the account is valid on the LDAP server. This vulnerability is fixed in Vault 1.14.1 and 1.13.5.

OpenSearch Security is a plugin for OpenSearch that offers encryption, authentication and authorization. There is an observable discrepancy in the authentication response time between calls where the user provided exists and calls where it does not. This issue only affects calls using the internal basic identity provider (IdP), and not other externally configured IdPs. Patches were released in versions 1.3.9 and 2.6.0, there are no workarounds.

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.

emoncms v11 and later was discovered to contain an information disclosure vulnerability which allows attackers to obtain the web directory path and other information leaked by the server via a crafted web request.

TN-5900 Series version 3.3 and prior versions is vulnearble to user enumeration vulnerability. The vulnerability may allow a remote attacker to determine whether a user is valid during password recovery through the web login page and enable a brute force attack with valid users.

Avaya IX Workforce Engagement v15.2.7.1195 - User Enumeration - Observable Response Discrepancy

A username enumeration issue was discovered in Medicine Tracker System 1.0. The login functionality allows a malicious user to guess a valid username due to a different response time from invalid usernames. When one enters a valid username, the response time increases depending on the length of the supplied password.

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.

When supplied with a random MAC address, Snap One OvrC cloud servers will return information about the device. The MAC address of devices can be enumerated in an attack and the OvrC cloud will disclose their information.

The HCL Domino AppDev Pack IAM service is susceptible to a User Account Enumeration vulnerability.   During a failed login attempt a difference in messages could allow an attacker to determine if the user is valid or not.  The attacker could use this information to focus a brute force attack on valid users.

AMI BMC contains a vulnerability in the IPMI handler, where an unauthorized attacker can use certain oracles to guess a valid username, which may lead to information disclosure.

A vulnerability has been identified in Mendix Forgot Password (Mendix 7 compatible) (All versions < V3.7.1), Mendix Forgot Password (Mendix 8 compatible) (All versions < V4.1.1), Mendix Forgot Password (Mendix 9 compatible) (All versions < V5.1.1). The affected versions of the module contain an observable response discrepancy issue that could allow an attacker to retrieve sensitive information.

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

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.