GHSA-4vpc-5jx4-cfqg User enumeration leak using switch user functionality in Symfony

• Packagist symfony/security-http: >= 4.1.0, < 4.2.12 → fixed in 4.2.12 • Packagist symfony/security-http: >= 4.3.0, < 4.3.8 → fixed in 4.3.8 • Packagist symfony/symfony: >= 4.1.0, < 4.2.12 → fixed in 4.2.12 • Packagist symfony/symfony: >= 4.3.0, < 4.3.8 → fixed in 4.3.8

An issue was discovered in Symfony 4.2.0 to 4.2.11 and 4.3.0 to 4.3.7. The ability to enumerate users was possible due to different handling depending on whether the user existed when making unauthorized attempts to use the switch users functionality. This is related to symfony/security.