CVE intelligence and bounded remediation

CVE-2021-32693 — Symfony is a PHP framework for web and console applications and a set of reusable PHP components

High CVSS 8.8

Symfony is a PHP framework for web and console applications and a set of reusable PHP components. A vulnerability related to firewall authentication is in Symfony starting with version 5.3.0 and prior to 5.3.2. When an application defines multiple firewalls, the token authenticated by one of the firewalls was available for all other firewalls. This could be abused when the application defines different providers for each part of the application, in such a situation, a user authenticated on a part of the application could be considered authenticated on the rest of the application. Starting in version 5.3.2, a patch ensures that the authenticated token is only available for the firewall that generates it.

Severity
High
CVSS
8.8 (3.1)
Published
2021-06-17
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-287

Affected products

  • sensiolabs / symfony

Matched remediation archetype

Authentication bypass and missing authentication

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Check exposure

  • Map every affected endpoint and protocol path, including alternate ports, legacy routes, recovery flows, service accounts, and machine-to-machine access.
  • Confirm which deployments enable the affected authentication mode and whether the interface is reachable from untrusted networks.
  • Review session, token, credential, and proxy trust configuration without attempting account takeover.

Remediate safely

  • Apply the supported fix and centralize fail-closed authentication before protected request handling.
  • Remove default or embedded credentials, rotate affected secrets and sessions, and bind authentication decisions to the intended audience and channel.
  • Add negative tests for alternate routes, malformed or absent credentials, recovery flows, and proxy-derived identity.

Authoritative sources

Complete CVE record and remediation plan

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