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Improper Neutralization of Special Elements used in a Command ('Command Injection')

CVE-2014-3556

Medium
6.8/10

Summary

The STARTTLS implementation in mail/ngx_mail_smtp_handler.c in the SMTP proxy in nginx 1.5.x and 1.6.x before 1.6.1 and 1.7.x before 1.7.4 does not properly restrict I/O buffering, which allows man-in-the-middle attackers to insert commands into encrypted SMTP sessions by sending a cleartext command that is processed after TLS is in place, related to a "plaintext command injection" attack, a similar issue to CVE-2011-0411.

  • MEDIUM
  • NETWORK
  • NONE
  • PARTIAL
  • PARTIAL
  • PARTIAL

CWE-77 - Command Injection

A command injection attack involves injecting an operating system command through the data input, which gets executed on the host operating system with the privileges of the victimized application. The impact of a command injection attack may range from loss of data confidentiality and integrity to unauthorized remote access to the hosting system. The attack may cause serious data breaches and system takeover.

References

Advisory Timeline

  • Published