Command Injection in nginx - CVE-2014-3556
Published: December 29, 2014 / Updated: August 9, 2020
Vulnerability identifier: #VU40985
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2014-3556
CWE-ID: CWE-77
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: F5 Networks
Affected software:
nginx
nginx
Detailed vulnerability description
The vulnerability allows a remote non-authenticated attacker to gain access to sensitive information.
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.
How to mitigate CVE-2014-3556
Install update from vendor's website.