Authentication Bypass
Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.
How It Works
Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications. Instead of cracking passwords through brute force, attackers manipulate the authentication process itself to gain unauthorized entry. This typically occurs through one of several pathways: exploiting hardcoded credentials embedded in source code or configuration files, manipulating parameters in authentication requests to skip verification steps, or leveraging broken session management that fails to properly validate user identity.
The attack flow often begins with reconnaissance to identify authentication endpoints and their underlying logic. Attackers may probe for default administrative credentials that were never changed, test whether certain URL paths bypass login requirements entirely, or intercept and modify authentication tokens to escalate privileges. In multi-step authentication processes, flaws in state management can allow attackers to complete only partial verification steps while still gaining full access.
More sophisticated variants exploit single sign-on (SSO) or OAuth implementations where misconfigurations in trust relationships allow attackers to forge authentication assertions. Parameter tampering—such as changing a "role=user" field to "role=admin" in a request—can trick poorly designed systems into granting elevated access without proper verification.
Impact
- Complete account takeover — attackers gain full control of user accounts, including administrative accounts, without knowing legitimate credentials
- Unauthorized data access — ability to view, modify, or exfiltrate sensitive information including customer data, financial records, and intellectual property
- System-wide compromise — admin-level access enables installation of backdoors, modification of security controls, and complete infrastructure takeover
- Lateral movement — bypassed authentication provides a foothold for moving deeper into networks and accessing additional systems
- Compliance violations — unauthorized access triggers breach notification requirements and regulatory penalties
Real-World Examples
CrushFTP suffered a critical authentication bypass allowing attackers to access file-sharing functionality without any credentials. The vulnerability enabled direct server-side template injection, leading to remote code execution on affected systems. Attackers actively exploited this in the wild to establish persistent access to enterprise file servers.
Palo Alto's Expedition migration tool contained a flaw permitting attackers to reset administrative credentials without authentication. This allowed complete takeover of the migration environment, potentially exposing network configurations and security policies being transferred between systems.
SolarWinds Web Help Desk (CVE-2024-28987) shipped with hardcoded internal credentials that could not be changed through normal administrative functions. Attackers discovering these credentials gained full administrative access to helpdesk systems containing sensitive organizational information and user data.
Mitigation
- Implement multi-factor authentication (MFA) — requires attackers to compromise additional verification factors beyond bypassed primary authentication
- Eliminate hardcoded credentials — use secure credential management systems and rotate all default credentials during deployment
- Enforce authentication on all endpoints — verify every request requires valid authentication; no "hidden" administrative paths should exist
- Implement proper session management — use cryptographically secure session tokens, validate on server-side, enforce timeout policies
- Apply principle of least privilege — limit damage by ensuring even authenticated users only access necessary resources
- Regular security testing — conduct penetration testing specifically targeting authentication logic and flows
Recent CVEs (32857)
A vulnerability was found in the 389 Directory Server that allows expired passwords to access the database to cause improper authentication. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A flaw was found in Quarkus. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
BigAnt Software BigAnt Server v5.6.06 was discovered to contain incorrect access control. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
The IBM Spectrum Protect 8.1.14.000 server could allow a remote attacker to bypass security restrictions, caused by improper enforcement of access controls. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity.
The matchmaking servers of Bandai Namco FromSoftware Dark Souls III through 2022-03-19 allow remote attackers to send arbitrary push requests to clients via a RequestSendMessageToPlayers request. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Piwigo v12.2.0 was discovered to contain an information leak via the action parameter in /admin/maintenance_actions.php. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An authentication issue was addressed with improved state management. Rated low severity (CVSS 3.3), this vulnerability is low attack complexity. No vendor patch available.
The GSMA authentication panel could be presented on the lock screen. Rated medium severity (CVSS 6.1), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
This issue was addressed with improved checks. Rated medium severity (CVSS 4.6), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
This issue was addressed with improved checks. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
This issue was addressed with improved checks. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
The issue was addressed with improved permissions logic. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
A use-after-free flaw was found in the Linux kernel’s FUSE filesystem in the way a user triggers write(). Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
OpenVPN 2.1 until v2.4.12 and v2.5.6 may enable authentication bypass in external authentication plug-ins when more than one of them makes use of deferred authentication replies, which allows an. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
Improper authentication in Veeam Backup & Replication 9.5U3, 9.5U4,10.x and 11.x component used for Microsoft System Center Virtual Machine Manager (SCVMM) allows attackers execute arbitrary code via. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Veeam Backup & Replication 10.x and 11.x has Incorrect Access Control (issue 1 of 2). Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
RunAsSpc 4.0 uses a universal and recoverable encryption key. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
When connecting to a certain port Axeda agent (All versions) and Axeda Desktop Server for Windows (All versions) may allow an attacker to send certain XML messages to a specific port without proper. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
When connecting to a certain port Axeda agent (All versions) and Axeda Desktop Server for Windows (All versions) may allow an attacker to send a certain command to a specific port without. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Axeda agent (All versions) and Axeda Desktop Server for Windows (All versions) may allow an attacker to send certain commands to a specific port without authentication. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Axeda agent (All versions) and Axeda Desktop Server for Windows (All versions) uses hard-coded credentials for its UltraVNC installation. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
A missing permission check in Jenkins Release Helper Plugin 1.3.3 and earlier allows attackers with Overall/Read permission to connect to an attacker-specified URL using attacker-specified. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
A missing permission check in Jenkins Kubernetes Continuous Deploy Plugin 2.3.1 and earlier allows attackers with Overall/Read permission to connect to an attacker-specified SSH server using. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
A missing permission check in Jenkins Kubernetes Continuous Deploy Plugin 2.3.1 and earlier allows attackers with Overall/Read permission to enumerate credentials IDs of credentials stored in Jenkins. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
A missing permission check in Jenkins Extended Choice Parameter Plugin 346.vd87693c5a_86c and earlier allows attackers with Overall/Read permission to connect to an attacker-specified URL. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
A missing permission check in Jenkins CloudBees AWS Credentials Plugin 189.v3551d5642995 and earlier allows attackers with Overall/Read permission to connect to an AWS service using an. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Bareos is open source software for backup, archiving, and recovery of data for operating systems. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
CometD is a scalable comet implementation for web messaging. Rated high severity (CVSS 8.1), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Volto is a ReactJS-based frontend for the Plone Content Management System. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable. This Improper Authentication vulnerability could allow attackers to bypass authentication mechanisms to gain unauthorized access.
Timescale TimescaleDB 1.x and 2.x before 2.5.2 may allow privilege escalation during extension installation. Rated high severity (CVSS 8.0), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
An issue was discovered in OpenSSH before 8.9. Rated low severity (CVSS 3.7), this vulnerability is remotely exploitable, no authentication required. This Improper Authentication vulnerability could allow attackers to bypass authentication mechanisms to gain unauthorized access.
The public API error causes for the attacker to be able to bypass API access control. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Missing Authorization in GitHub repository saleor/saleor prior to 3.1.2. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.
Improper Authorization in GitHub repository cobbler/cobbler prior to 3.3.2. Rated critical severity (CVSS 9.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
Missing Authorization in GitHub repository gogs/gogs prior to 0.12.5. Rated critical severity (CVSS 9.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
The following Yokogawa Electric products hard-code the password for CAMS server applications: CENTUM VP versions from R5.01.00 to R5.04.20 and versions from R6.01.00 to R6.08.00, Exaopc versions from. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
CAMS for HIS Server contained in the following Yokogawa Electric products improperly authenticate the receiving packets. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
The following Yokogawa Electric products do not change the passwords of the internal Windows accounts from the initial configuration: CENTUM VP versions from R5.01.00 to R5.04.20 and versions from. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
FreeTAKServer 1.9.8 contains a hardcoded Flask secret key which allows attackers to create crafted cookies to bypass authentication or escalate privileges. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
An access control issue in the component /ManageRoute/postRoute of FreeTAKServer v1.9.8 allows unauthenticated attackers to cause a Denial of Service (DoS) via an unusually large amount of created. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Improper Authorization in GitHub repository orchardcms/orchardcore prior to 1.3.0. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.
The TP-240 (aka tp240dvr) component in Mitel MiCollab before 9.4 SP1 FP1 and MiVoice Business Express through 8.1 allows remote attackers to obtain sensitive information and cause a denial of service. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
SAP Financial Consolidation - version 10.1, does not perform necessary authorization checks for updating homepage messages, resulting for an unauthorized user to alter the maintenance system message. Rated medium severity (CVSS 5.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Under certain conditions, SAP NetWeaver (Real Time Messaging Framework) - version 7.50, allows an attacker to access information which could lead to information gathering for further exploits and. Rated medium severity (CVSS 5.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Due to missing authorization check, SAP NetWeaver Application Server for ABAP - versions 700, 701, 702, 731, allows an authenticated attacker, to access content on the start screen of any transaction. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Power Line Communications PLC4TRUCKS J2497 trailer brake controllers implement diagnostic functions which can be invoked by replaying J2497 messages. Rated critical severity (CVSS 9.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Improper access control vulnerability in Samsung Account prior to version 13.1.0.1 allows attackers to access to the authcode for sign-in. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. No vendor patch available.
Improper access control vulnerability in BixbyTouch prior to version 2.2.00.6 in China models allows untrusted applications to load arbitrary URL and local files in webview. Rated low severity (CVSS 3.3), this vulnerability is low attack complexity. No vendor patch available.
Improper authentication in One UI Home prior to SMR Mar-2022 Release 1 allows attacker to generate pinned-shortcut without user consent. Rated low severity (CVSS 3.3), this vulnerability is low attack complexity. No vendor patch available.
Improper authentication in Samsung Lock and mask apps setting prior to SMR Mar-2022 Release 1 allows attacker to change enable/disable without authentication. Rated medium severity (CVSS 4.6), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Use of a hard-coded cryptographic key pair by the telnetd_startup service allows an attacker on the local area network to obtain a root shell on the device over telnet. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. Public exploit code available and no vendor patch available.
Improper physical access control and use of hard-coded credentials in /etc/passwd permits an attacker with physical access to obtain a root shell via an unprotected UART port on the device. Rated medium severity (CVSS 6.8), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An Improper access control vulnerability in StRetailModeReceiver in Wear OS 3.0 prior to Firmware update MAR-2022 Release allows untrusted applications to reset default app settings without a proper. Rated low severity (CVSS 3.3), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Luocms v2.0 is affected by an incorrect access control vulnerability. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
The Simple Diagnostics Agent - versions 1.0 up to version 1.57, does not perform any authentication checks for functionalities that can be accessed via localhost on http port 3005. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. Public exploit code available and no vendor patch available.
Acer QuickAccess 2.01.300x before 2.01.3030 and 3.00.30xx before 3.00.3038 contains a local privilege escalation vulnerability. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
Acer Care Center 4.00.30xx before 4.00.3042 contains a local privilege escalation vulnerability. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
YzmCMS v6.3 is affected by broken access control. Rated critical severity (CVSS 9.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In preloader (usb), there is a possible permission bypass due to a missing proper image authentication. Rated medium severity (CVSS 6.6), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
In ims service, there is a possible AT command injection due to a missing permission check. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
In ims service, there is a possible escalation of privilege due to a missing permission check. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
In vpu, there is a possible escalation of privilege due to a missing permission check. Rated medium severity (CVSS 6.7), this vulnerability is low attack complexity. No vendor patch available.
Missing Authorization in GitHub repository go-gitea/gitea prior to 1.16.4. Rated high severity (CVSS 7.1), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.
Shopware is an open commerce platform based on the Symfony php Framework and the Vue javascript framework. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This Improper Authentication vulnerability could allow attackers to bypass authentication mechanisms to gain unauthorized access.
A CWE-294: Authentication Bypass by Capture-replay vulnerability exists that could cause an unauthenticated connection to the UPS when a malformed connection is sent. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A CWE-287: Improper Authentication vulnerability exists that could cause an attacker to arbitrarily change the behavior of the UPS when a key is leaked and used to upload malicious firmware. Rated critical severity (CVSS 9.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Windows HTML Platforms Security Feature Bypass Vulnerability. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Microsoft Intune Portal for iOS Security Feature Bypass Vulnerability. Rated low severity (CVSS 3.3), this vulnerability is low attack complexity. No vendor patch available.
Microsoft Word Security Feature Bypass Vulnerability. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Exposure of Private Personal Information to an Unauthorized Actor in GitHub repository alextselegidis/easyappointments prior to 1.4.3. Rated critical severity (CVSS 9.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
Icinga Web 2 is an open source monitoring web interface, framework and command-line interface. Rated medium severity (CVSS 5.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This Incorrect Authorization vulnerability could allow attackers to bypass authorization checks to access restricted resources.
A vulnerability has been identified in Mendix Applications using Mendix 7 (All versions < V7.23.29). Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
A vulnerability has been identified in Mendix Forgot Password Appstore module (All versions >= V3.3.0 < V3.5.1). Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
A vulnerability has been identified in Mendix Runtime V7 (All versions < V7.23.29), Mendix Runtime V8 (All versions < V8.18.16), Mendix Runtime V9 (All versions < V9.13 only with Runtime Custom. Rated high severity (CVSS 8.1), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Evmos is the Ethereum Virtual Machine (EVM) Hub on the Cosmos Network. Rated high severity (CVSS 7.4), this vulnerability is remotely exploitable, no authentication required. This Improper Authentication vulnerability could allow attackers to bypass authentication mechanisms to gain unauthorized access.
Missing Authorization in GitHub repository salesagility/suitecrm prior to 7.12.5. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.
Missing Authorization in GitHub repository salesagility/suitecrm prior to 7.12.5. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.
The UsersWP WordPress plugin before 1.2.3.1 is missing access controls when updating a user avatar, and does not make sure file names for user avatars are unique, allowing a logged in user to. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
The Smart Forms WordPress plugin before 2.6.71 does not have authorisation in its rednao_smart_forms_entries_list AJAX action, allowing any authenticated users, such as subscriber, to download. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A DNS rebinding issue in ReadyMedia (formerly MiniDLNA) before 1.3.1 allows a remote web server to exfiltrate media files. Rated high severity (CVSS 7.4), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
Under certain ldap conditions, Cacti authentication can be bypassed with certain credential types. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A vulnerability was found in the Linux kernel’s cgroup_release_agent_write in the kernel/cgroup/cgroup-v1.c function. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. Actively exploited in the wild (cisa kev) and public exploit code available.
The biometric lock in Devolutions Password Hub for iOS before 2021.3.4 allows attackers to access the application because of authentication bypass. Rated medium severity (CVSS 6.6), this vulnerability is low attack complexity. No vendor patch available.
An Insecure Direct Object Reference (IDOR) vulnerability in OpenEMR 6.0.0 allows any authenticated attacker to access and modify unauthorized areas via a crafted POST request to. Rated high severity (CVSS 8.1), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
bluetoothd from bluez incorrectly saves adapters' Discoverable status when a device is powered down, and restores it when powered up. Rated medium severity (CVSS 6.5), this vulnerability is no authentication required, low attack complexity. This Incorrect Authorization vulnerability could allow attackers to bypass authorization checks to access restricted resources.
Home Owners Collection Management System v1.0 was discovered to contain hardcoded credentials which allows attackers to escalate privileges and access the admin panel. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Zoho ManageEngine SharePoint Manager Plus before 4329 allows account takeover because authorization is mishandled. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Improper Authorization in GitHub repository webmin/webmin prior to 1.990. Rated high severity (CVSS 8.1), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.
Improper Access Control to Remote Code Execution in GitHub repository webmin/webmin prior to 1.990. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.
Extensis Portfolio v4.0 was discovered to contain hardcoded credentials which allows attackers to gain administrator privileges. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Quick Facts
- Typical Severity
- CRITICAL
- Category
- auth
- Total CVEs
- 32857