TrueCrypt 7.1a has many vulnerabilities that can be seen here in a third party security assessment by iSEC: https://opencryptoaudit.org/reports/iSec_Final_Open_Crypto_Audit_Project_TrueCrypt_Security_Assessment.pdf

This can also be verified by going to the SourceForge TrueCrypt website here: http://www.truecrypt.org/ or here: http://truecrypt.sourceforge.net/ (down for maintenance at the time of writing this)

A more secure replacement is VeraCrypt here: https://veracrypt.codeplex.com/ that was built on TrueCrypt 7.1a with vulnerabilities fixed and enhanced security features.