CVE 2017-16653
An issue was discovered in Symfony before 2.7.38, 2.8.31, 3.2.14, 3.3.13, 3.4-BETA5, and 4.0-BETA5. The current implementation of CSRF protection in Symfony (Version >=2) does not use different tokens for HTTP and HTTPS; therefore the token is subject to MITM attacks on HTTP and can then be used in an HTTPS context to do CSRF attacks.
See the
CVE page on Mitre.org
for more details.