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Vulnerability details: VCID-pa1n-3at9-qbhu
Vulnerability ID VCID-pa1n-3at9-qbhu
Aliases CVE-2016-0772
Summary 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."
Status Published
Exploitability 2.0
Weighted Severity 4.3
Risk 8.6
Affected and Fixed Packages Package Details
Weaknesses (0)
There are no known CWE.
System Score Found at
cvssv3 4.8 https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2016-0772.json
epss 0.07644 https://api.first.org/data/v1/epss?cve=CVE-2016-0772
epss 0.07644 https://api.first.org/data/v1/epss?cve=CVE-2016-0772
epss 0.07644 https://api.first.org/data/v1/epss?cve=CVE-2016-0772
epss 0.07644 https://api.first.org/data/v1/epss?cve=CVE-2016-0772
cvssv2 5.8 https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
Reference id Reference type URL
https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2016-0772.json
https://api.first.org/data/v1/epss?cve=CVE-2016-0772
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-0772
https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
1303647 https://bugzilla.redhat.com/show_bug.cgi?id=1303647
CVE-2016-0772 Exploit https://github.com/tintinweb/pub/tree/11f6ebda59ad878377df78351f8ab580660d0024/pocs/cve-2016-0772
CVE-2016-0772 Exploit https://gitlab.com/exploit-database/exploitdb/-/blob/main/exploits/multiple/local/43500.txt
GLSA-201701-18 https://security.gentoo.org/glsa/201701-18
RHSA-2016:1626 https://access.redhat.com/errata/RHSA-2016:1626
RHSA-2016:1627 https://access.redhat.com/errata/RHSA-2016:1627
RHSA-2016:1628 https://access.redhat.com/errata/RHSA-2016:1628
RHSA-2016:1629 https://access.redhat.com/errata/RHSA-2016:1629
RHSA-2016:1630 https://access.redhat.com/errata/RHSA-2016:1630
USN-3134-1 https://usn.ubuntu.com/3134-1/
Data source Exploit-DB
Date added Jan. 11, 2018
Description Python smtplib 2.7.11 / 3.4.4 / 3.5.1 - Man In The Middle StartTLS Stripping
Ransomware campaign use Unknown
Source publication date July 3, 2016
Exploit type local
Platform multiple
Source update date Jan. 11, 2018
Source URL https://github.com/tintinweb/pub/tree/11f6ebda59ad878377df78351f8ab580660d0024/pocs/cve-2016-0772
Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N Found at https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2016-0772.json
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: AV:N/AC:M/Au:N/C:P/I:P/A:N Found at https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
Exploitability (E) Access Vector (AV) Access Complexity (AC) Authentication (Au) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

high

functional

unproven

proof_of_concept

not_defined

local

adjacent_network

network

high

medium

low

multiple

single

none

none

partial

complete

none

partial

complete

none

partial

complete
Exploit Prediction Scoring System (EPSS)
Percentile 0.92028
EPSS Score 0.07644
Published At June 4, 2026, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2026-06-04T17:08:35.654642+00:00 Debian Importer Import https://security-tracker.debian.org/tracker/data/json 38.6.0