CWE-204— Observable Response Discrepancy

userSpice 4.3.24 contains a username enumeration vulnerability that allows unauthenticated attackers to discover valid usernames by sending POST requests to the existingUsernameCheck.php endpoint. Attackers can submit usernames and analyze…

An authorization bypass vulnerability exists in the REST API of multiple versions of OpenNMS Meridian and Horizon. The /rest/** Spring Security filter chains authorize requests with intercept-url rules that name the HTTP method as an upper…

Mojolicious versions from 4.59 before 9.48 for Perl expose a stable representation of the session CSRF token to a BREACH compression oracle. _csrf_token generates and caches one token per session and returns the same value on every call, …

Observable response discrepancy in Azure Stack HCI allows an unauthorized attacker to disclose information over a network.

User names used to access the web management interface are limited to the device identifier, which is a numerical identifier no more than 10 digits. A malicious actor can enumerate potential targets by incrementing or decrementing from …

Observable response discrepancy vulnerability in Rolantis Information Technologies Tourism Industry and Trade Co. Ltd. Agentis allows Account Footprinting. This issue affects Agentis: before 4.8.

Observable response discrepancy vulnerability in IKAS Technology Inc. Ikas E-Commerce Infrastructure allows Account Footprinting. This issue affects ikas E-Commerce Infrastructure: through 2026-07-13.

Observable response discrepancy vulnerability in GastroMenum GastroMenum Web Panel allows Account Footprinting. This issue affects GastroMenum Web Panel: before 31.08.2026.

Observable response discrepancy vulnerability in Menulux Software Inc. Menulux Portal allows Account Footprinting. This issue affects Menulux Portal: before 20260903211448.

Combodo iTop is a web based IT service management tool. Prior to 3.2.3, iTop returns different responses for valid/invalid usernames depending on multiple factors in the reset password mechanism, leading to user enumeration. This issue has…

SiYuan before v3.7.4 is missing authorization checks in 17 block metadata/content endpoints in kernel/api/block.go (including getRefText, checkBlockExist, and getBlockBreadcrumb). These handlers are gated only by basic authentication (mode…

MinIO is a high-performance object storage system. Prior to RELEASE.2026-03-17T21-25-16Z, MinIO AIStor's STS (Security Token Service) AssumeRoleWithLDAPIdentity endpoint is vulnerable to LDAP credential brute-forcing due to two combined we…

Observable response discrepancy vulnerability in OpenText™ Vertica allows Password Brute Forcing.   The vulnerability could lead to Password Brute Forcing in Vertica management console application.This issue affects Vertica: from 10.0 …

CWE-204: Observable Response Discrepancy

An unauthenticated remote attacker can enumerate valid user names from an unprotected endpoint.

A vulnerability in SonicWall SMA100 password change API allows a remote unauthenticated attacker to perform SMA100 username enumeration based on the server responses. This vulnerability impacts 10.2.1.2-24sv, 10.2.0.8-37sv and earlier 10.x…

In mymbCONNECT24, mbCONNECT24 <= 2.9.0 an unauthenticated user can enumerate valid backend users by checking what kind of response the server sends for crafted invalid login attempts.

DokuWiki 2018-04-22b contains a username enumeration vulnerability in its password reset functionality that allows attackers to identify valid user accounts. Attackers can submit different usernames to the password reset endpoint and disti…

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.

In Eclipse Milo versions 0.6.0 through 1.1.4, username-token processing returns distinguishable errors for invalid RSA PKCS#1 v1.5 padding and other authentication failures, allowing an on-path attacker who captures a victim's `Basic128Rsa…

An observable response discrepancy vulnerability in the SonicWall SMA1000 series appliances allows a remote attacker to enumerate SSL VPN user credentials.

FOSSBilling is an open source billing and client-management platform. From 0.1.0 until 0.8.7, the unauthenticated POST /api/guest/client/create endpoint reveals whether a submitted email belongs to a registered client because guest signup …

Frappe is a full-stack web application framework. Prior to 15.115.0 and 16.27.0, the public request-data web form and PersonalDataDownloadRequest class in frappe/website/doctype/personal_data_download_request/personal_data_download_request…

Lemmy is a link aggregator and forum for the fediverse. Prior to 0.19.19 and 1.0.0-beta.1, Lemmy's login endpoint in crates/api/api/src/local_user/login.rs returns different errors depending on whether the username_or_email value exists. L…

WPGraphQL provides a GraphQL API for WordPress sites. From 2.0.0 until 2.15.1, the deprecated user field on SendPasswordResetEmailPayload lets an unauthenticated caller distinguish existing author-class accounts through the sendPasswordRes…

vantage6 is an open-source infrastructure for privacy preserving analysis. Versions prior to 5.0.0 provide an initial user with username `root` and password `root`. This is not ideal because attackers know that almost all vantage6 servers …

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 us…

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…

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.

Cosmos provides users the ability self-host a home server by acting as a secure gateway to your application, as well as a server manager. By monitoring the error code returned in the login, it is possible to figure out whether a user exist…

Snipe-IT before 8.7.0 fails to properly enforce the viewKeys authorization gate in CSV export and API index endpoints, allowing authenticated users with only licenses.view permission to access product keys. Attackers can download all licen…

During authorization checks in SAP Human Capital Management for SAP S/4HANA, the system returns specific messages. Due to this, an authenticated user with low privileges could guess and enumerate the content shown, beyond their authorized …

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 …

Icinga 2 is an open source monitoring system. In Icinga 2 versions 2.4 through 2.15.0, filter expressions provided to the various /v1/objects endpoints could access variables or objects that would otherwise be inaccessible for the user. Th…

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 hi…

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.

IBM DS8900F HMC 89.21.19.0, 89.21.31.0, 89.30.68.0, 89.32.40.0, and 89.33.48.0 could allow an authenticated user to arbitrarily read files after enumerating file names.

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 …

InHand Networks IR615 Router's Versions 2.3.0.r4724 and 2.3.0.r4870 authentication process response indicates and validates the existence of a username. This may allow an attacker to enumerate different user accounts.

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 "Fo…

Trivision NC-227WF firmware 5.80 (build 20141010) login mechanism reveals whether a username exists or not by returning different error messages ("Unknown user" vs. "Wrong password"), allowing an attacker to enumerate valid usernames.

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 fr…

FOSSBilling is a free, open-source billing and client management system. Prior to version 0.8.0, the password reset confirmation endpoint `/client/reset-password-confirm/:hash` is handled by a non-API controller and is not covered by FOSSB…

Go package IceWhaleTech/CasaOS-UserService provides user management functionalities to CasaOS. The Casa OS Login page has disclosed the username enumeration vulnerability in the login page which was patched in version 0.4.7. This issue in …

CasaOS-UserService provides user management functionalities to CasaOS. Starting in version 0.4.4.3 and prior to version 0.4.7, the Casa OS Login page disclosed the username enumeration vulnerability in the login page. An attacker can enume…

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…

When a WSO2 product is configured to use an external user store, the system fails to adequately obscure the existence or validity of usernames during authentication attempts. This oversight allows an attacker to repeatedly query the authen…

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…

WPGraphQL before 2.24.2 contains an information disclosure vulnerability that allows unauthenticated attackers to determine object existence through distinct error responses. Attackers can iterate IDs against deleteMediaItem, updateMediaIt…

Cacti is an open source performance and fault management framework. Prior to version 1.2.31, a User Enumeration vulnerability allows an attacker to identify valid usernames on the Cacti service. When a user attempts to log in, the applicat…