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…
- 6.8MediumCVSS base score
- 7.8%Exploitation in 30 daysEPSS · top 5.3% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
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.
Timeline
ID reserved
By redhat
- 8 months later
· 8 months later
Published
- 10 years later
· 10 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 2.0 | Medium6.8 | AV:N/AC:M/Au:N/C:P/I:P/A:P |
- EPSS (exploitation in 30 days)
- 7.8% · top 5.3% of all CVEs (9 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.8.
Affected products
n/a
- affected n/a
References
4
- HPSBOV03227 (opens in a new tab)vendor-advisoryx_refsource_HPx_transferred
- https://bugzilla.redhat.com/show_bug.cgi?id=1126891 (opens in a new tab)x_refsource_CONFIRMx_transferred
- [nginx-announce] 20140805 nginx security advisory (CVE-2014-3556) (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
- http://nginx.org/download/patch.2014.starttls.txt (opens in a new tab)x_refsource_CONFIRMx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2014-3539 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2014-3556)Record last updated .