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    CVE-2016-0772

    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."

    Published:Jun 11, 2016
    Last Modified:Apr 12, 2025
    EPS:Sep 2, 2016
    EPSS Score:0.11062
    CVSS Score:6.5

    Affected Products

    Vendor
    Python
    Product
    Python
    Vendor
    Redhat
    Product
    Enterprise Linux
    Vendor
    Redhat
    Product
    Rhel Software Collections

    Exploits

    https://www.exploit-db.com/exploits/43500

    Common Weakness Enumeration

    CWE-693 Protection Mechanism Failure

    Common Attack Pattern Enumeration and Classification (CAPEC)

    CAPEC-1 Accessing Functionality Not Properly Constrained by ACLs
    CAPEC-107 Cross Site Tracing
    CAPEC-127 Directory Indexing
    CAPEC-17 Using Malicious Files
    CAPEC-20 Encryption Brute Forcing
    CAPEC-22 Exploiting Trust in Client
    CAPEC-237 Escaping a Sandbox by Calling Code in Another Language
    CAPEC-36 Using Unpublished Interfaces or Functionality
    CAPEC-477 Signature Spoofing by Mixing Signed and Unsigned Content
    CAPEC-480 Escaping Virtualization
    CAPEC-51 Poison Web Service Registry
    CAPEC-57 Utilizing REST's Trust in the System Resource to Obtain Sensitive Data
    CAPEC-59 Session Credential Falsification through Prediction
    CAPEC-65 Sniff Application Code
    CAPEC-668 Key Negotiation of Bluetooth Attack (KNOB)
    CAPEC-74 Manipulating State
    CAPEC-87 Forceful Browsing

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    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
    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

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High