nginx < 1.7.4 SMTP STARTTLS Command Injection
Medium Web Application Scanning Plugin ID 98957
Synopsis
nginx < 1.7.4 SMTP STARTTLS Command Injection
Description
According to the self-reported version in the server response header, the version of nginx installed on the remote host is 1.5.6 or higher, 1.6.x prior to 1.6.1, or 1.7.x prior to 1.7.4. It is, therefore, affected by a command injection vulnerability. A flaw exists in the function '
ngx_mail_smtp_starttls' within the file 'src/mail/ngx_mail_smtp_handler.c' whereby input to the STARTTLS command is not properly sanitized. This could allow a remote attacker in a privileged network position to obtain sensitive information by injecting commands into an SSL session. This issue is
exploitable only when nginx is used as an SMTP proxy.
Note that the scanner has not tested for these issues but has instead relied only on the application's self-reported version number.
Solution
Upgrade to nginx 1.7.4 or later.