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)
-
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.
-
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
230 results · Feed
-
High 7.5
Combodo iTop: User enumeration via password reset
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 been fixed in versi…
-
High 8.6
Azure Stack HCI Information Disclosure Vulnerability
Observable response discrepancy in Azure Stack HCI allows an unauthorized attacker to disclose information over a network.
-
Medium 6.9
Frappe: User Enumeration via PDDR
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.py return distingui…
-
Medium 6.9
Lemmy: Login Endpoint User Enumeration via HTTP Response Code Differential
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. LocalUserView::find_b…
-
High 7.5
SiYuan before v3.7.4 Missing Authorization via block API
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 (model.CheckAuth) and lac…
-
Low 3.7
automad Password Reset Endpoint UserController.php requestPasswordResetToken response discrepancy
A vulnerability was determined in automad up to 2.0.0-beta.32. This vulnerability affects the function requestPasswordResetToken of the file automad/src/server/Controllers/API/UserController.php of the component Password Reset Endpoint. This manipulation of t…
-
Medium 5.3
PostgreSQL observable response discrepancy with non-default scram_iterations provides user existence oracle
Observable response discrepancy in PostgreSQL SCRAM authentication allows an unauthenticated user to test the existence of a user via observing the SCRAM iteration count. This requires the probed user to have a non-default scram_iterations count, because the …
-
Medium 5.3
Budibase: Account Enumeration via Login Lockout Response Differential
Budibase is an open-source low-code platform. Prior to 3.39.25, POST /api/global/auth/:tenantId/login incremented the failure counter in packages/worker/src/api/controllers/global/auth.ts only for existing users, while packages/worker/src/middleware/emailLock…
-
Medium 5.3
bluewave-labs Checkmate - User Enumeration via Differential HTTP Response in Password Recovery
A user enumeration vulnerability in bluewave-labs/Checkmate through 2.1.0 allows an unauthenticated remote attacker to determine whether a given email address is registered. The POST /api/v1/auth/recovery/request endpoint returns HTTP 200 for registered email…
-
Medium 5.3
Cluster Existence Oracle via Unauthenticated Import Endpoint
The endpoint /v3/import/{token}_{clusterId}.yaml retrieves the cluster object before validating the token. When a valid cluster ID references a cluster that has private registry secrets configured, a nil pointer dereference in pkg/systemtemplate/private_regis…
-
Critical 9.1
In Eclipse Milo versions 0.6.0 through 1.1.4, username-token processing returns distinguishable errors for invalid RSA …
-
Medium 5.3
Username Enumeration via Differential Login Responses in Bilin Software's HUMANIST Digital Human Resources
Observable response discrepancy vulnerability in Bilin Software and Informatics Consultancy Inc. HUMANIST Digital Human Resources allows Account Footprinting. This issue affects HUMANIST Digital Human Resources: from 26.0 before 26.1.
-
Medium 6.9
WPGraphQL has deprecated `user` field on SendPasswordResetEmailPayload that leaks user existence + profile (defeats explicit anti-enumeration design)
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 sendPasswordResetEmail mutation and…
-
Medium 5.3
XRDP is vulnerable to a server timing attack, leading to user enumeration
xrdp is an open source RDP server. Versions 0.10.6 and prior contain a timing side-channel vulnerability in the login interface. Due to a discrepancy in response processing times, a remote attacker can infer the existence of a username on the system, leading …
-
Medium 5.3
HCL Aftermarket EPC is vulnerable to attack since It was found that a malicious actor can use brute-force techniques to…
-
Medium 4.3
An issue was discovered in cyrus-imapd in Cyrus IMAP through 3.12.2. There is an ESEARCH cross-user content oracle. By …
-
Critical 9.1
Mojolicious versions from 4.59 before 9.48 for Perl expose a stable representation of the session CSRF token to a BREACH compression oracle
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, and _csrf_field place…
-
Low 3.7
Information Disclosure vulnerability in SAP HANA Extended Application Services classic model (User Self Service)
SAP HANA Database (user self service tools) allows an unauthenticated user to send specially crafted requests that produce distinguishable responses, enabling enumeration of valid user accounts and email addresses. Successful exploitation could allow the atta…
-
Medium 5.3
Rejetto HFS < 3.2.1 Username Enumeration via Login Response Differences
Rejetto HFS 3.0.0 through 3.2.0 returns observably different responses from its login endpoint depending on whether the submitted username exists. A remote unauthenticated attacker can use this to confirm valid account names, including the default admin accou…
-
Low —
Webauthn: SimpleFakeCredentialGenerator with an empty secret produces predictable fake credentials, weakening username enumeration protection
## Impact `Webauthn\SimpleFakeCredentialGenerator` is the library-provided default implementation of the `FakeCredentialGenerator` interface. It returns a stable list of decoy `PublicKeyCredentialDescriptor` objects for a given username so that an assertion r…
-
Low 2.3
SFTP REALPATH path-existence oracle allowing filesystem enumeration outside configured root
Observable Response Discrepancy vulnerability in Erlang OTP ssh (ssh_sftpd module) allows an authenticated SFTP user to enumerate the existence of files and directories outside the configured root directory. The SSH_FXP_REALPATH handler in ssh_sftpd calls rel…
-
Medium 6.9
User Enumeration in MCO
MCO is vulnerable to User Enumeration through authentication-related functionalities. The application returns distinguishable responses for valid and invalid users during username reminder and password reset operations. An attacker can leverage these differen…
-
Medium —
Pterodactyl Panel: Client email change endpoint allows enumeration of accounts in system
### Summary An unprotected user enumeration vulnerability exists in the account email update endpoint, allowing authenticated users to verify whether email addresses are registered on the panel through automated requests without rate limiting or CAPTCHA prote…
-
Medium 5.3
Ghost: Member existence leak via magic link sign-in response
Ghost is a Node.js content management system. From 5.18.0 until 6.21.1, a discrepancy in responses from the members signin endpoints made it possible for an unauthenticated attacker to determine whether a given email address belongs to a registered member of …
-
Medium 6.9
Vantage6: Set admin user and password from environment or configuration
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 have a user with use…
-
Medium 6.3
FOSSBilling's password reset confirmation endpoint lacks rate limiting
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 FOSSBilling's rate limite…
-
Medium 5.3
FreeScout: User Account Enumeration via Password Reset Response Differentiation
FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. Prior to 1.8.219, the password reset endpoint returns visually distinct responses depending on whether the submitted email address belongs to an existing user account, allowing…
-
Medium 5.3
AVideo CVE-2026-43881 incomplete fix - `objects/mention.json.php:17` is an unauthenticated user enumeration
WWBN AVideo is an open source video platform. In 29.0 and earlier, objects/mention.json.php has no User::loginCheck() or admin gate. It only has an entry guard: preg_match('/^@/', $_REQUEST['term']) and hard-coded rowCount=10. This enables unauthenticated use…
-
Critical 9.8
userSpice 4.3.24 Username Enumeration via existingUsernameCheck.php
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 response text for t…
-
Medium 5.3
Statamic: Email enumeration via forgot password endpoint
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 enumerat…
-
Medium 5.3
Username Enumeration via Email OTP Flow in Multiple WSO2 Products Allows User Account Discovery
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 engine…
-
Low 3.7
Industrial Application Software IAS Canias ERP Login RMI doAction response discrepancy
A vulnerability was found in Industrial Application Software IAS Canias ERP 8.03. The impacted element is the function doAction of the component Login RMI Interface. Performing a manipulation results in observable response discrepancy. The attack is possible …
-
Medium —
Lemmy resend-verification endpoint exposes registered email addresses to unauthenticated users
## Summary The unauthenticated resend-verification endpoint returns different responses for registered and unregistered email addresses. A malicious third party can submit candidate addresses to `/api/v4/account/auth/resend_verification_email` and distinguish…
-
Medium 5.3
Cisco Identity Services Engine Observable Response Discrepancy Vulnerability
A vulnerability in an identity management API endpoint of Cisco ISE could allow an unauthenticated, remote attacker to enumerate valid user accounts on an affected device. This vulnerability exists because error messages are observed when the affected API end…
-
Medium 5.0
Vulnerability in the MySQL Shell product of Oracle MySQL (component: Shell: Core Client). Supported versions that are a…
-
Medium 5.3
OpenAEV Vulnerable to Username/Email Enumeration Through Differential HTTP Responses in Password Reset API
OpenAEV is an open source platform allowing organizations to plan, schedule and conduct cyber adversary simulation campaign and tests. Starting in version 1.11.0 and prior to version 2.0.13, the /api/reset endpoint behaves differently depending on whether the…
-
Medium 5.3
ChurchCRM: Username Enumeration via Differential Response in Public Login API
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 val…
-
Medium 6.5
Information Disclosure vulnerability in SAP Human Capital Management for SAP S/4HANA
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 scope. This leads to…
-
High 7.2
An observable response discrepancy vulnerability in the SonicWall SMA1000 series appliances allows a remote attacker to…
-
Medium 5.3
Saleor has a user enumeration vulnerability due to different error messages
Saleor is an e-commerce platform. From 2.10.0 to before 3.23.0a3, 3.22.47, 3.21.54, and 3.20.118, the requestEmailChange() mutation was revealing the existence of user-provided email addresses in error messages. This vulnerability is fixed in 3.23.0a3, 3.22.4…