Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
system/libraries/Email.php in CodeIgniter before 3.1.3 allows remote attackers to execute arbitrary code by leveraging control over the email->from field to insert sendmail command-line arguments.
CWE-74 - Injection
Listed as the number one web application security risk on the 'OWASP Top Ten', injection attacks are widespread and dangerous, especially in legacy applications. Injection attacks are a class of vulnerabilities in which an attacker injects untrusted data into a web application that gets processed by an interpreter, altering the program's execution. This can result in data loss/theft, loss of data integrity, denial of service, and even compromising the entire system.