Symfony
CVE-2016-2403
CRITICAL
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A07:2025 - Authentication Failures
ASVS 5.0
V6 - Authentication Authentication mechanism validation
MITRE ATT&CK
2 techniques across 2 tactics: Defense Evasion, Initial Access The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS score of 9.8 (CRITICAL). Attack characteristics: network attack vector, low complexity, no privileges required, no user interaction not required. EPSS exploitation probability: 0.15%. |
| Exploit ScenarioDerived | A remote attacker could bypass authentication mechanisms to gain unauthorized access by sending crafted requests to the affected application. No authentication is required to exploit this vulnerability. |
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Alert meAnalysisAI
Symfony before 2.8.6 and 3.x before 3.0.6 allows remote attackers to bypass authentication by logging in with an empty password and valid username, which triggers an unauthenticated bind. Rated critical severity (CVSS 9.8), 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.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. Implement multi-factor authentication, enforce strong password policies, use proven authentication frameworks.
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 3 packages in composer
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
This vulnerability is classified as Improper Authentication (CWE-287), which allows attackers to bypass authentication mechanisms to gain unauthorized access. Symfony before 2.8.6 and 3.x before 3.0.6 allows remote attackers to bypass authentication by logging in with an empty password and valid username, which triggers an unauthenticated bind. Affected products include: Sensiolabs Symfony. Version information: before 2.8.6.
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionCVE.org
Symfony before 2.8.6 and 3.x before 3.0.6 allows remote attackers to bypass authentication by logging in with an empty password and valid username, which triggers an unauthenticated bind.
Threat Intelligence Overview
NVD
CVE.org
EPSS
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.
Affected Products (CPE)CVE.org
FragmentListener in the HttpKernel component in Symfony 2.3.19 through 2.3.28, 2.4.9 through 2.4.10, 2.5.4 through 2.5.1
In Symfony before 2.7.51, 2.8.x before 2.8.50, 3.x before 3.4.26, 4.x before 4.1.12, and 4.2.x before 4.2.7, when servic
Twig before 2.4.4 allows Server-Side Template Injection (SSTI) via the search search_key parameter. Rated critical sever
Insufficient verification of payment-claim state in the Sylius e-commerce platform (versions before 2.1.16 and 2.2.9) le
Incorrect authorization in the Sylius Shop API lets anyone holding an order token submit arbitrary payment actions - mos
Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Rated high severity (C
Symfony versions up to 5.4.51 contains a vulnerability that allows attackers to operations being performed on an uninten
Reflected Cross-site scripting (XSS) vulnerability in the web profiler in SensioLabs Symfony 3.3.6 allows remote attacke
Symphony process is a module for the Symphony PHP framework which executes commands in sub-processes. Rated critical sev
An issue was discovered in Symfony 3.4.0 through 3.4.34, 4.2.0 through 4.2.11, and 4.3.0 through 4.3.7. Rated critical s
An issue was discovered in Symfony before 4.2.12 and 4.3.x before 4.3.8. Rated critical severity (CVSS 9.8), this vulner
In Symfony before 2.7.51, 2.8.x before 2.8.50, 3.x before 3.4.26, 4.x before 4.1.12, and 4.2.x before 4.2.7, HTTP Method
GitHub PoC
Exploit-DB