CVE-2016-0772 EXPLOIT
6.5
MEDIUM · CVSS 3.0 · EPSS 14.5% (pctl 97)
Patch early
A public exploit exists.
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."
Scoring
| CVSS | 6.5 (MEDIUM, v3.0) |
|---|---|
| Vector | CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N |
| EPSS | 14.52% — more likely to be exploited than 97% of all CVEs |
| Weakness | CWE-693 |
| On CISA KEV | no |
| Public exploit | yes |
| Published | 2016-09-02 |
| Last modified | 2026-06-17 |
Affected (1)
| Vendor | Product |
|---|---|
| python | python |
Public exploits
| Source | Title | Date |
|---|---|---|
| exploit-db | Python smtplib 2.7.11 / 3.4.4 / 3.5.1 - Man In The Middle StartTLS Stripping | 2016-07-03 |
References
- http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00040.html
- http://rhn.redhat.com/errata/RHSA-2016-1626.html
- http://rhn.redhat.com/errata/RHSA-2016-1627.html
- http://rhn.redhat.com/errata/RHSA-2016-1628.html
- http://rhn.redhat.com/errata/RHSA-2016-1629.html
- http://rhn.redhat.com/errata/RHSA-2016-1630.html
- http://www.openwall.com/lists/oss-security/2016/06/14/9
- http://www.securityfocus.com/bid/91225
- http://www.splunk.com/view/SP-CAAAPSV
- http://www.splunk.com/view/SP-CAAAPUE
- https://bugzilla.redhat.com/show_bug.cgi?id=1303647
- https://docs.python.org/3.4/whatsnew/changelog.html#python-3-4-5
- https://docs.python.org/3.5/whatsnew/changelog.html#python-3-5-2
- https://hg.python.org/cpython/raw-file/v2.7.12/Misc/NEWS
- https://hg.python.org/cpython/rev/b3ce713fb9be
- https://hg.python.org/cpython/rev/d590114c2394
- https://lists.debian.org/debian-lts-announce/2019/02/msg00011.html
- https://security.gentoo.org/glsa/201701-18
- http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00040.html
- http://rhn.redhat.com/errata/RHSA-2016-1626.html
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