Authentication Bypass

auth CRITICAL

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 (37769)

CVE-2023-28197

EPSS 0% CVSS 3.3

LOW Monitor

An access issue was addressed with additional sandbox restrictions. Rated low severity (CVSS 3.3), this vulnerability is no authentication required, low attack complexity. No vendor patch available.

Authentication Bypass Information Disclosure Apple +1

NVD

CVE-2022-42816

EPSS 0% CVSS 5.5

MEDIUM This Month

A logic issue was addressed with improved state management. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. No vendor patch available.

Authentication Bypass Apple macOS

NVD

CVE-2023-48783

EPSS 0% CVSS 5.4

MEDIUM This Month

An Authorization Bypass Through User-Controlled Key vulnerability [CWE-639] affecting PortiPortal version 7.2.1 and below, version 7.0.6 and below, version 6.0.14 and below, version 5.3.8 and below. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Authentication Bypass Fortinet Fortiportal

NVD

CVE-2023-46712

EPSS 0% CVSS 7.2

HIGH This Week

A improper access control in Fortinet FortiPortal version 7.0.0 through 7.0.6, Fortinet FortiPortal version 7.2.0 through 7.2.1 allows attacker to escalate its privilege via specifically crafted HTTP. Rated high severity (CVSS 7.2), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Authentication Bypass Fortinet Fortiportal

NVD

CVE-2023-50172 PHP

EPSS 0% CVSS 5.3

MEDIUM POC This Month

A recovery notification bypass vulnerability exists in the userRecoverPass.php captcha validation functionality of WWBN AVideo dev master commit 15fed957fb. Rated medium severity (CVSS 5.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.

PHP Authentication Bypass Avideo +1

NVD

CVE-2023-49810 PHP

EPSS 0% CVSS 7.3

HIGH POC This Week

A login attempt restriction bypass vulnerability exists in the checkLoginAttempts functionality of WWBN AVideo dev master commit 15fed957fb. Rated high severity (CVSS 7.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.

Authentication Bypass Avideo Wwbn

NVD

CVE-2023-6158

EPSS 0% CVSS 6.5

MEDIUM PATCH This Month

The EventON - WordPress Virtual Event Calendar Plugin plugin for WordPress is vulnerable to unauthorized modification of data and loss of data due to a missing capability check on the. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This Missing Authorization vulnerability could allow attackers to access resources or perform actions without proper authorization checks.

WordPress Authentication Bypass Eventon +3

NVD VulDB

CVE-2023-48252

EPSS 1% CVSS 8.8

HIGH This Week

The vulnerability allows an authenticated remote attacker to perform actions exceeding their authorized access via crafted HTTP requests. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.