Symfony Multiple Security Vulnerabilities



Date Discovered

November 13, 2019


Symfony is prone to multiple security vulnerabilities: An attacker may leverage these issues to bypass certain security restrictions and perform unauthorized actions, execute arbitrary code, obtain sensitive information or cause denial-of-service conditions. Symfony versions 2.8.0 through 2.8.51, 3.4.0 through 3.4.34, 4.2.0 through 4.2.11 and 4.3.0 through 4.3.7 are vulnerable.

Technologies Affected

  • SensioLabs Symfony 2.8.0
  • SensioLabs Symfony 2.8.43
  • SensioLabs Symfony 2.8.44
  • SensioLabs Symfony 2.8.48
  • SensioLabs Symfony 2.8.49
  • SensioLabs Symfony 2.8.50
  • SensioLabs Symfony 2.8.51
  • SensioLabs Symfony 3.4.0
  • SensioLabs Symfony 3.4.13
  • SensioLabs Symfony 3.4.14
  • SensioLabs Symfony 3.4.19
  • SensioLabs Symfony 3.4.20
  • SensioLabs Symfony 3.4.25
  • SensioLabs Symfony 3.4.26
  • SensioLabs Symfony 3.4.34
  • SensioLabs Symfony 4.2.0
  • SensioLabs Symfony 4.2.1
  • SensioLabs Symfony 4.2.11
  • SensioLabs Symfony 4.2.6
  • SensioLabs Symfony 4.2.7
  • SensioLabs Symfony 4.3.0
  • SensioLabs Symfony 4.3.7


Block external access at the network boundary, unless external parties require service.
If global access isn't needed, filter access to the affected computer at the network boundary. Restricting access to only trusted computers and networks might greatly reduce the likelihood of a successful attack.

Run all software as a nonprivileged user with minimal access rights.
To limit the consequences of a successful exploit, run server processes within a restricted environment using facilities such as chroot or jail.

Deploy network intrusion detection systems to monitor network traffic for malicious activity.
Deploy NIDS to monitor network traffic for signs of anomalous or suspicious activity. This may indicate exploit attempts or activity that results from successful exploits.

Implement multiple redundant layers of security.
Consider using additional tools to further restrict access for the vulnerable applications via access control security policies.

Implement multiple redundant layers of security.
Various memory-protection schemes (such as nonexecutable and randomly mapped memory segments) may hinder an attacker's ability to exploit this vulnerability to execute arbitrary code.

Updates are available. Please see the references or vendor advisory for more information.



Felix Sokoliuk, Christophe Coevoet, Ivan Novikov and Nicolas Grekas.

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