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 (32785)

CVE-2023-37492

EPSS 0% CVSS 6.5

MEDIUM This Month

SAP NetWeaver Application Server ABAP and ABAP Platform - versions SAP_BASIS 700, SAP_BASIS 701, SAP_BASIS 702, SAP_BASIS 731, SAP_BASIS 740, SAP_BASIS 750, SAP_BASIS 752, SAP_BASIS 753, SAP_BASIS. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

SAP Authentication Bypass Netweaver Application Server Abap

NVD

CVE-2023-37491

EPSS 0% CVSS 8.8

HIGH This Week

The ACL (Access Control List) of SAP Message Server - versions KERNEL 7.22, KERNEL 7.53, KERNEL 7.54, KERNEL 7.77, RNL64UC 7.22, RNL64UC 7.22EXT, RNL64UC 7.53, KRNL64NUC 7.22, KRNL64NUC 7.22EXT, can. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

SAP Authentication Bypass Message Server

NVD

CVE-2023-37483

EPSS 1% CVSS 9.8

CRITICAL Act Now

SAP PowerDesigner - version 16.7, has improper access control which might allow an unauthenticated attacker to run arbitrary queries against the back-end database via Proxy. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

SAP Authentication Bypass Powerdesigner

NVD

CVE-2023-36926

EPSS 0% CVSS 5.3

MEDIUM This Month

Due to missing authentication check in SAP Host Agent - version 7.22, an unauthenticated attacker can set an undocumented parameter to a particular compatibility value and in turn call read. Rated medium severity (CVSS 5.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

SAP Authentication Bypass Host Agent

NVD

CVE-2023-39363 PyPI

EPSS 1% CVSS 9.1

CRITICAL POC PATCH Act Now

Vyper is a Pythonic Smart Contract Language for the Ethereum Virtual Machine (EVM). Rated critical severity (CVSS 9.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.

Authentication Bypass Vyper

NVD GitHub

CVE-2023-39349 PyPI

EPSS 1% CVSS 8.1

HIGH POC PATCH This Week

Sentry is an error tracking and performance monitoring platform. Rated high severity (CVSS 8.1), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.

Authentication Bypass Sentry

NVD GitHub

CVE-2023-38157

EPSS 2% CVSS 6.5

MEDIUM PATCH This Month

Microsoft Edge (Chromium-based) Security Feature Bypass Vulnerability. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity.

Authentication Bypass Google Microsoft +1

NVD

CVE-2023-32783

EPSS 3% CVSS 7.5

HIGH POC This Week

The event analysis component in Zoho ManageEngine ADAudit Plus 7.1.1 allows an attacker to bypass audit detection by creating or renaming user accounts with a "$" symbol suffix. 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.

Zoho Authentication Bypass Manageengine Adaudit Plus

NVD

CVE-2023-4194

EPSS 0% CVSS 5.5

MEDIUM PATCH This Month

A flaw was found in the Linux kernel's TUN/TAP functionality. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. This Access of Resource Using Incompatible Type (Type Confusion) vulnerability could allow attackers to execute arbitrary code by exploiting type confusion in the application.

Linux Authentication Bypass Memory Corruption +4

NVD

CVE-2023-20800

EPSS 0% CVSS 6.5

MEDIUM This Month

In imgsys, there is a possible system crash due to a mssing ptr check. Rated medium severity (CVSS 6.5), this vulnerability is low attack complexity. No vendor patch available.

Privilege Escalation Authentication Bypass Yocto +1

NVD

CVE-2023-33912

EPSS 0% CVSS 5.5

MEDIUM This Month

In Contacts service, there is a possible missing permission check.This could lead to local information disclosure with no additional execution privileges. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. No vendor patch available.