Arbitrary Command Injection Affecting nginx package, versions <1.6.1-1


Severity

Recommended
0.0
medium
0
10

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Threat Intelligence

EPSS
7.83% (94th percentile)

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  • Snyk IDSNYK-ECHOLATEST-NGINX-18011575
  • published18 Jul 2026
  • disclosed29 Dec 2014

Introduced: 29 Dec 2014

CVE-2014-3556  (opens in a new tab)
CWE-77  (opens in a new tab)

How to fix?

Upgrade Echo:latest nginx to version 1.6.1-1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream nginx package and not the nginx package as distributed by Echo. See How to fix? for Echo:latest relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1