UBUNTU-CVE-2021-3738

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    UBUNTU-CVE-2021-3738

    Published: 9 Nov 2021Last Modified: 22 Apr 2026
    Upstream:
    CVE-2021-3738
    Aliases:
    USN-5142-1

    Summary:

    Details: In DCE/RPC it is possible to share the handles (cookies for resource state) between multiple connections via a mechanism called 'association groups'. These handles can reference connections to our sam.ldb database. However while the database was correctly shared, the user credentials state was only pointed at, and when one connection within that association group ended, the database would be left pointing at an invalid 'struct session_info'. The most likely outcome here is a crash, but it is possible that the use-after-free could instead allow different user state to be pointed at and this might allow more privileged access.

    References: https://ubuntu.com/security/CVE-2021-3738, https://www.samba.org/samba/security/CVE-2021-3738.html, https://www.samba.org/samba/history/samba-4.13.14.html, https://ubuntu.com/security/notices/USN-5142-1, https://www.cve.org/CVERecord?id=CVE-2021-3738

    Affected packages

    Package

    Name: samba

    Purl: pkg:deb/ubuntu/samba@2:4.3.11+dfsg-0ubuntu0.14.04.20+esm15?arch=source&distro=esm-infra-legacy/trusty

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 0
    Fixed -None

    Affected versions

    2:3.6.18-1ubuntu3

    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-2021-3738 | CVE-DB