UBUNTU-CVE-2021-32066

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    UBUNTU-CVE-2021-32066

    Published: 15 Jul 2021Last Modified: 22 Apr 2026
    Upstream:
    CVE-2021-32066
    Aliases:
    USN-5020-1

    Summary:

    Details: An issue was discovered in Ruby through 2.6.7, 2.7.x through 2.7.3, and 3.x through 3.0.1. Net::IMAP does not raise an exception when StartTLS fails with an an unknown response, 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."

    References: https://ubuntu.com/security/CVE-2021-32066, https://www.ruby-lang.org/en/news/2021/07/07/starttls-stripping-in-net-imap/, https://github.com/ruby/ruby/commit/a21a3b7d23704a01d34bd79d09dc37897e00922a, https://ubuntu.com/security/notices/USN-5020-1, https://www.cve.org/CVERecord?id=CVE-2021-32066

    Affected packages

    Package

    Name: ruby2.3

    Purl: pkg:deb/ubuntu/[email protected]~ubuntu16.04.16+esm1?arch=source&distro=esm-infra/xenial

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 0
    Fixed -2.3.1-2~ubuntu16.04.16+esm1

    Affected versions

    2.3.0-1
    2.3.0-2
    2.3.0-4ubuntu2
    2.3.0-4ubuntu3
    2.3.0-5ubuntu1
    2.3.1-2~16.04
    2.3.1-2~16.04.2
    2.3.1-2~16.04.4
    2.3.1-2~16.04.5
    2.3.1-2~16.04.6
    2.3.1-2~16.04.7
    2.3.1-2~16.04.9
    2.3.1-2~16.04.10
    2.3.1-2~16.04.11
    2.3.1-2~16.04.12
    2.3.1-2~ubuntu16.04.13
    2.3.1-2~ubuntu16.04.14
    2.3.1-2~ubuntu16.04.15
    2.3.1-2~ubuntu16.04.16

    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
    UBUNTU-CVE-2021-32066 | CVE-DB