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.

A vulnerability in the TLS handler of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software for Cisco Firepower 1000 Series firewalls could allow an unauthenticated, remote attacker to gain access to sensitive information. The vulnerability is due to improper implementation of countermeasures against the Bleichenbacher attack for cipher suites that rely on RSA for key exchange. An attacker could exploit this vulnerability by sending crafted TLS messages to the device, which would act as an oracle and allow the attacker to carry out a chosen-ciphertext attack. A successful exploit could allow the attacker to perform cryptanalytic operations that may allow decryption of previously captured TLS sessions to the affected device. To exploit this vulnerability, an attacker must be able to perform both of the following actions: Capture TLS traffic that is in transit between clients and the affected device Actively establish a considerable number of TLS connections to the affected device

An issue was discovered in Arm Mbed TLS before 2.23.0. Because of a side channel in modular exponentiation, an RSA private key used in a secure enclave could be disclosed.

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.

An issue was discovered in Arm Mbed TLS before 2.23.0. A side channel allows recovery of an ECC private key, related to mbedtls_ecp_check_pub_priv, mbedtls_pk_parse_key, mbedtls_pk_parse_keyfile, mbedtls_ecp_mul, and mbedtls_ecp_mul_restartable.

An issue was discovered in MediaWiki before 1.35.1. Missing users (accounts that don't exist) and hidden users (accounts that have been explicitly hidden due to being abusive, or similar) that the viewer cannot see are handled differently, exposing sensitive information about the hidden status to unprivileged viewers. This exists on various code paths.

Umbraco is a free and open source .NET content management system. Prior to versions 10.8.10 and 13.8.1, based on an analysis of the timing of post login API responses, it's possible to determine whether an account exists. The issue is patched in versions 10.8.10 and 13.8.1. No known workarounds are available.

An issue was discovered in the SecurePoll extension for MediaWiki through 1.35.1. The non-admin vote list contains a full vote timestamp, which may provide unintended clues about how a voting process unfolded.

When binding against a DN during authentication, the reply from 389-ds-base will be different whether the DN exists or not. This can be used by an unauthenticated attacker to check the existence of an entry in the LDAP database.

An issue was discovered in UTI Mutual fund Android application 5.4.18 and prior, allows attackers to brute force enumeration of usernames determined by the error message returned after invalid credentials are attempted.

An email address enumeration vulnerability exists in the password reset function of Rocket.Chat through 3.9.1.

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 Stop User Enumeration WordPress plugin before version 1.7.3 blocks REST API /wp-json/wp/v2/users/ requests for non-authorized users. However, this can be bypassed by URL-encoding the API path.

In Legion of the Bouncy Castle BC before 1.61 and BC-FJA before 1.0.1.2, attackers can obtain sensitive information about a private exponent because of Observable Differences in Behavior to Error Inputs. This occurs in org.bouncycastle.crypto.encodings.OAEPEncoding. Sending invalid ciphertext that decrypts to a short payload in the OAEP Decoder could result in the throwing of an early exception, potentially leaking some information about the private exponent of the RSA private key performing the encryption.

Silverware Games is a premium social network where people can play games online. Prior to version 1.3.6, the Password Recovery form would throw an error if the specified email was not found in our database. It would only display the "Enter the code" form if the email is associated with a member of the site. Since version 1.3.6, the "Enter the code" form is always returned, showing the message "If the entered email is associated with an account, a code will be sent now". This change prevents potential violators from determining if our site has a user with the specified email.

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.

A vulnerability in Cisco Integrated Management Controller could allow an unauthenticated, remote attacker to enumerate valid usernames within the vulnerable application. The vulnerability is due to differences in authentication responses sent back from the application as part of an authentication attempt. An attacker could exploit this vulnerability by sending authentication requests to the affected application. A successful exploit could allow the attacker to confirm the names of administrative user accounts for use in further attacks.There are no workarounds that address this vulnerability.

Pritunl 1.29.2145.25 allows attackers to enumerate valid VPN usernames via a series of /auth/session login attempts. Initially, the server will return error 401. However, if the username is valid, then after 20 login attempts, the server will start responding with error 400. Invalid usernames will receive error 401 indefinitely. Note: This has been disputed by the vendor as not a vulnerability. They argue that this is an intended design

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.

A vulnerability has been identified in Mendix Runtime V10 (All versions < V10.21.0), Mendix Runtime V10.12 (All versions < V10.12.16), Mendix Runtime V10.18 (All versions < V10.18.5), Mendix Runtime V10.6 (All versions < V10.6.22), Mendix Runtime V8 (All versions < V8.18.35), Mendix Runtime V9 (All versions < V9.24.34). Affected applications allow for entity enumeration due to distinguishable responses in certain client actions. This could allow an unauthenticated remote attacker to list all valid entities and attribute names of a Mendix Runtime-based application.

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

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.

An issue was discovered in OpenSlides before 4.2.5. During login at the /system/auth/login/ endpoint, the system's response times differ depending on whether a user exists in the system. The timing discrepancy stems from the omitted hashing of the password (e.g., more than 100 milliseconds).

In BIG-IP 15.0.0, 14.1.0-14.1.0.6, 14.0.0-14.0.0.5, 13.0.0-13.1.1.5, 12.1.0-12.1.4.1, 11.5.1-11.6.4, BIG-IQ 7.0.0, 6.0.0-6.1.0,5.2.0-5.4.0, iWorkflow 2.3.0, and Enterprise Manager 3.1.1, the Configuration utility login page may not follow best security practices when handling a malicious request.

IBM CICS TX Advanced 10.1 could disclose sensitive information to a remote attacker due to observable discrepancy in HTTP responses. IBM X-Force ID: 260814.

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

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.

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.

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

An issue was discovered in the ProofreadPage (aka Proofread Page) extension for MediaWiki through 1.39.3. In includes/Page/PageContentHandler.php and includes/Page/PageDisplayHandler.php, hidden users can be exposed via public interfaces.

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.

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.

An issue discovered in Elenos ETG150 FM transmitter v3.12 allows attackers to enumerate user accounts based on server responses when credentials are submitted.

The login function of Mealie v1.0.0beta-2 allows attackers to enumerate existing usernames by timing the server's response time.

Cloud Native Computing Foundation Harbor before 1.10.3 and 2.x before 2.0.1 allows resource enumeration because unauthenticated API calls reveal (via the HTTP status code) whether a resource exists.

_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.

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.

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.

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

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 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.

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.

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.

The Reset Password feature in Pagekit 1.0.17 gives a different response depending on whether the e-mail address of a valid user account is entered, which might make it easier for attackers to enumerate accounts.

IBM Security QRadar EDR 3.12 could disclose sensitive information due to an observable login response discrepancy. IBM X-Force ID: 257697.

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.

An issue was discovered in ConnectWise Control (formerly known as ScreenConnect) 19.3.25270.7185. There is a user enumeration vulnerability, allowing an unauthenticated attacker to determine with certainty if an account exists for a given username.

SPIP before 3.1.11 and 3.2 before 3.2.5 provides different error messages from the password-reminder page depending on whether an e-mail address exists, which might help attackers to enumerate subscribers.

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.