RCE in F5 nginx

CVE-2014-3556

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.

Vulnerability class: Command Injection (OS Command Injection)

Published · last modified .

CVSS v2 metric

CVSS v2 base score 6.8 (Medium). Vector: AV:N/AC:M/Au:N/C:P/I:P/A:P. This CVE predates CVSS v3 and has no v3 score from NVD.

EPSS exploit prediction

EPSS: 0.078 (94.5th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 94th percentile — 94.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2014-3556: held from 0.078 to 0.078.

EPSS over last 30 days · oldest: 0.078 · newest: 0.078 · change: 0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2014-3556?
CVE-2014-3556 is a vulnerability in F5 nginx, classified under Command Injection. Published 2014-12-29.
Is CVE-2014-3556 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.