CVE-2016-0772
Summary
| CVE | CVE-2016-0772 |
|---|---|
| State | PUBLISHED |
| Assigner | redhat |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2016-09-02 14:59:00 UTC |
| Updated | 2026-05-06 22:30:45 UTC |
| Description | The smtplib library in CPython (aka Python) before 2.7.12, 3.x before 3.4.5, and 3.5.x before 3.5.2 does not return an error when StartTLS fails, which might allow man-in-the-middle attackers to bypass the TLS protections by leveraging a network position between the client and the registry to block the StartTLS command, aka a "StartTLS stripping attack." |
Risk And Classification
Primary CVSS: v3.0 6.5 MEDIUM from [email protected]
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N
EPSS: 0.150300000 probability, percentile 0.963640000 (date 2026-07-22)
Problem Types: CWE-693 | n/a
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.0 | [email protected] | Primary | 6.5 | MEDIUM | CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N |
| 2.0 | [email protected] | Primary | 5.8 | AV:N/AC:M/Au:N/C:P/I:P/A:N |
CVSS v3.0 Breakdown
Attack Vector
NetworkAttack Complexity
HighPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
LowIntegrity
HighAvailability
NoneCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N
CVSS v2.0 Breakdown
Access Vector
NetworkAccess Complexity
MediumAuthentication
NoneConfidentiality
PartialIntegrity
PartialAvailability
NoneAV:N/AC:M/Au:N/C:P/I:P/A:N
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Application | Python | Python | 3.0 | All | All | All |
| Application | Python | Python | 3.0.1 | All | All | All |
| Application | Python | Python | 3.1.0 | All | All | All |
| Application | Python | Python | 3.1.1 | All | All | All |
| Application | Python | Python | 3.1.2 | All | All | All |
| Application | Python | Python | 3.1.3 | All | All | All |
| Application | Python | Python | 3.1.4 | All | All | All |
| Application | Python | Python | 3.1.5 | All | All | All |
| Application | Python | Python | 3.2.0 | All | All | All |
| Application | Python | Python | 3.2.1 | All | All | All |
| Application | Python | Python | 3.2.2 | All | All | All |
| Application | Python | Python | 3.2.3 | All | All | All |
| Application | Python | Python | 3.2.4 | All | All | All |
| Application | Python | Python | 3.2.5 | All | All | All |
| Application | Python | Python | 3.2.6 | All | All | All |
| Application | Python | Python | 3.3.0 | All | All | All |
| Application | Python | Python | 3.3.1 | All | All | All |
| Application | Python | Python | 3.3.2 | All | All | All |
| Application | Python | Python | 3.3.3 | All | All | All |
| Application | Python | Python | 3.3.4 | All | All | All |
| Application | Python | Python | 3.3.5 | All | All | All |
| Application | Python | Python | 3.3.6 | All | All | All |
| Application | Python | Python | 3.4.0 | All | All | All |
| Application | Python | Python | 3.4.1 | All | All | All |
| Application | Python | Python | 3.4.2 | All | All | All |
| Application | Python | Python | 3.4.3 | All | All | All |
| Application | Python | Python | 3.4.4 | All | All | All |
| Application | Python | Python | 3.5.0 | All | All | All |
| Application | Python | Python | 3.5.1 | All | All | All |
| Application | Python | Python | All | All | All | All |
Vendor Declared Affected Products
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| hg.python.org/cpython/raw-file/v2.7.12/Misc/NEWS | af854a3a-2127-422b-91ae-364da2661108 | hg.python.org | Release Notes |
| Splunk Enterprise 6.4.5 addresses multiple vulnerabilities | Splunk | af854a3a-2127-422b-91ae-364da2661108 | www.splunk.com | |
| Red Hat Customer Portal | af854a3a-2127-422b-91ae-364da2661108 | rhn.redhat.com | |
| Red Hat Customer Portal | af854a3a-2127-422b-91ae-364da2661108 | rhn.redhat.com | |
| cpython: d590114c2394 | af854a3a-2127-422b-91ae-364da2661108 | hg.python.org | Patch |
| Python: Multiple vulnerabilities (GLSA 201701-18) — Gentoo security | af854a3a-2127-422b-91ae-364da2661108 | security.gentoo.org | |
| oss-security - Python CVE-2016-0772: smtplib StartTLS stripping attack | af854a3a-2127-422b-91ae-364da2661108 | www.openwall.com | Mailing List |
| Changelog — Python 3.4.5 documentation | af854a3a-2127-422b-91ae-364da2661108 | docs.python.org | Release Notes |
| cpython: b3ce713fb9be | af854a3a-2127-422b-91ae-364da2661108 | hg.python.org | Patch |
| [security-announce] openSUSE-SU-2020:0086-1: important: Security update | af854a3a-2127-422b-91ae-364da2661108 | lists.opensuse.org | |
| Bug 1303647 – CVE-2016-0772 python: smtplib StartTLS stripping attack | af854a3a-2127-422b-91ae-364da2661108 | bugzilla.redhat.com | Issue Tracking, Third Party Advisory |
| Red Hat Customer Portal | af854a3a-2127-422b-91ae-364da2661108 | rhn.redhat.com | |
| Python smtplib CVE-2016-0772 Man in the Middle Security Bypass Vulnerability | af854a3a-2127-422b-91ae-364da2661108 | www.securityfocus.com | |
| [SECURITY] [DLA 1663-1] python3.4 security update | af854a3a-2127-422b-91ae-364da2661108 | lists.debian.org | |
| Red Hat Customer Portal | af854a3a-2127-422b-91ae-364da2661108 | rhn.redhat.com | |
| Red Hat Customer Portal | af854a3a-2127-422b-91ae-364da2661108 | rhn.redhat.com | |
| Changelog — Python 3.5.2 documentation | af854a3a-2127-422b-91ae-364da2661108 | docs.python.org | Release Notes |
| Splunk Enterprise 6.5.1 addresses multiple OpenSSL vulnerabilities | Splunk | af854a3a-2127-422b-91ae-364da2661108 | www.splunk.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
Legacy QID Mappings
- 730315 Splunk Enterprise and Light Security Update (SP-CAAAPSV) (SPL-128812)