FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. Prior to version 1.8.211, checkIpByMask() in app/Misc/Helper.php checks whether the input IP contains a / character. Plain IP addresses never contain /, so the function always returns false without checking any CIDR ranges. The entire 10.0.0.0/8 and 172.16.0.0/12 private ranges are unprotected. This issue has been patched in version 1.8.211.

Observable Discrepancy in Packagist snipe/snipe-it prior to v5.3.9.

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.

Teltonika’s Remote Management System versions prior to 4.10.0 contain a function that allows users to claim their devices. This function returns information based on whether the serial number of a device has already been claimed, the MAC address of a device has already been claimed, or whether the attempt to claim a device was successful. An attacker could exploit this to create a list of the serial numbers and MAC addresses of all devices cloud-connected to the Remote Management System.

Medtronic CareLink Network allows an unauthenticated remote attacker to initiate a request for security questions to an API endpoint that could be used to determine a valid user account. This issue affects CareLink Network: before December 4, 2025.

A vulnerability in Qlik Sense Enterprise on Windows could allow an remote attacker to enumerate domain user accounts. An attacker could exploit this vulnerability by sending authentication requests to an affected system. A successful exploit could allow the attacker to compare the response time that are returned by the affected system to determine which accounts are valid user accounts. Affected systems are only vulnerable if they have LDAP configured. The affected URI is /internal_forms_authentication/ the response time of the form is longer if the supplied user does not exists and shorter if the user exists.

An issue was discovered in eZ Publish Ibexa Kernel before 7.5.15.1. The /user/sessions endpoint can be abused to determine account existence.

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

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.

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.

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.

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.

IBM Aspera Console 3.3.0 through 3.4.8 could allow an attacker to enumerate usernames due to an observable response discrepancy.

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.

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.

The Page Restriction WordPress (WP) – Protect WP Pages/Post plugin for WordPress is vulnerable to Sensitive Information Exposure in all versions up to, and including, 1.3.6 via the WordPress core search feature. This makes it possible for unauthenticated attackers to extract sensitive data from posts that have been restricted to higher-level roles such as administrator.

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 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.

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.

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.

A CWE-204 "Observable Response Discrepancy" in the login page in Q-Free MaxTime less than or equal to version 2.11.0 allows an unauthenticated remote attacker to enumerate valid usernames via crafted HTTP requests.

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.

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.

On Coldcard MK1 and MK2 devices, a side channel for the row-based OLED display was found. The power consumption of each row-based display cycle depends on the number of illuminated pixels, allowing a partial recovery of display contents. For example, a hardware implant in the USB cable might be able to leverage this behavior to recover confidential secrets such as the PIN and BIP39 mnemonic. In other words, the side channel is relevant only if the attacker has enough control over the device's USB connection to make power-consumption measurements at a time when secret data is displayed. The side channel is not relevant in other circumstances, such as a stolen device that is not currently displaying secret data. On Coldcard MK1 and MK2 devices, a side channel for the row-based OLED display was found. The power consumption of each row-based display cycle depends on the number of illuminated pixels, allowing a partial recovery of display contents. For example, a hardware implant in the USB cable might be able to leverage this behavior to recover confidential secrets such as the PIN and BIP39 mnemonic. In other words, the side channel is relevant only if the attacker has enough control over the device's USB connection to make power-consumption measurements at a time when secret data is displayed. The side channel is not relevant in other circumstances, such as a stolen device that is not currently displaying secret data. NOTE: At Coinkite, we’ve already mitigated it, even though we feel strongly that it is not a legitimate issue. In our opinion, it is both unproven (might not even work) and also completely impractical—even if it could be made to work perfectly

In CentOS-WebPanel.com (aka CWP) CentOS Web Panel 0.9.8.848, the Login process allows attackers to check whether a username is valid by comparing response times.

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.

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

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.

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.

During an annual penetration test conducted on behalf of Axis Communications, Truesec discovered a flaw in the VAPIX Device Configuration framework that allowed for unauthenticated username enumeration through the VAPIX Device Configuration SSH Management API.

IBM Guardium Data Encryption (GDE) 5.0.0.2 behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor, which could facilitate username enumeration. IBM X-Force ID: 213856.

Observable Response Discrepancy in SICK FTMg AIR FLOW SENSOR with Partnumbers 1100214, 1100215, 1100216, 1120114, 1120116, 1122524, 1122526 allows a remote attacker to gain information about valid usernames by analyzing challenge responses from the server via the REST interface.

Meow hash 0.5/calico does not sufficiently thwart key recovery by an attacker who can query whether there's a collision in the bottom bits of the hashes of two messages, as demonstrated by an attack against a long-running web service that allows the attacker to infer collisions by measuring timing differences.

A vulnerability has been identified in Gridscale X Prepay (All versions < V4.2.1). The affected application is 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.

CyberArk Identity 21.5.131, when handling an invalid authentication attempt, sometimes reveals whether the username is valid. In certain authentication policy configurations with MFA, the API response length can be used to differentiate between a valid user and an invalid one (aka Username Enumeration). Response differentiation enables attackers to enumerate usernames of valid application users. Attackers can use this information to leverage brute-force and dictionary attacks in order to discover valid account information such as passwords.

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

Variable response times in the AWS Sign-in IAM user login flow allowed for the use of brute force enumeration techniques to identify valid IAM usernames in an arbitrary AWS account.

TREK is a collaborative travel planner. Prior to 3.0.18, early return on missing user during login flow allowed an attacker to enumerate valid user accounts via response timing discrepancy. When an email address existed in the database, the backend performed a bcrypt password comparison before returning a 401 Unauthorized, adding ~370 ms of latency. When the email did not exist, the backend returned immediately (~10 ms). This ~14× timing difference could be detected without any difference in HTTP status codes or response bodies. This vulnerability is fixed in 3.0.18.

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 enumerate valid users, which can aid in follow-up credential-based attacks. This vulnerability is fixed in 5.73.21 and 6.15.0.

The Splunk Enterprise REST API allows enumeration of usernames via the lockout error message. The potential vulnerability impacts Splunk Enterprise instances before 8.1.7 when configured to repress verbose login errors.

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 valid users with incorrect passwords. An unauthenticated attacker can exploit this difference to enumerate valid usernames, with no rate limiting or account lockout to impede the process. This issue has been fixed in version 7.2.0.

Observable Response Discrepancy in GitHub repository answerdev/answer prior to 1.0.6.

Observable Timing Discrepancy in GitHub repository answerdev/answer prior to 1.0.6.

Observable Discrepancy in GitHub repository healthchecks/healthchecks prior to v2.6.

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

Redmine before 4.0.9 and 4.1.x before 4.1.3 allows an attacker to learn the values of internal authentication keys by observing timing differences in string comparison operations within SysController and MailHandlerController.

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 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

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.51 and 9.6.0-alpha.40, the Pages route and legacy PublicAPI route for resending email verification links return distinguishable responses depending on whether the provided username exists and has an unverified email. This allows an unauthenticated attacker to enumerate valid usernames by observing different redirect targets. The existing emailVerifySuccessOnInvalidEmail configuration option, which is enabled by default and protects the API route against this, did not apply to these routes. This issue has been patched in versions 8.6.51 and 9.6.0-alpha.40.