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    CVE-2021-20254

    A flaw was found in samba. The Samba smbd file server must map Windows group identities (SIDs) into unix group ids (gids). The code that performs this had a flaw that could allow it to read data beyond the end of the array in the case where a negative cache entry had been added to the mapping cache. This could cause the calling code to return those values into the process token that stores the group membership for a user. The highest threat from this vulnerability is to data confidentiality and integrity.

    Published:Apr 29, 2021
    Last Modified:Nov 21, 2024
    EPS:May 5, 2021
    EPSS Score:0.00389
    CVSS Score:6.8

    Affected Products

    Vendor
    Debian
    Product
    Debian Linux
    Vendor
    Fedoraproject
    Product
    Fedora
    Vendor
    Redhat
    Product
    Enterprise Linux
    Vendor
    Redhat
    Product
    Rhel Aus
    Vendor
    Redhat
    Product
    Rhel E4s
    Vendor
    Redhat
    Product
    Rhel Eus
    Vendor
    Redhat
    Product
    Rhel Tus
    Vendor
    Redhat
    Product
    Storage
    Vendor
    Samba
    Product
    Samba

    Exploits

    No exploit reference

    Common Weakness Enumeration

    CWE-125 Out-of-bounds Read

    Common Attack Pattern Enumeration and Classification (CAPEC)

    CAPEC-540 Overread Buffers

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    References

    https://bugzilla.redhat.com/show_bug.cgi?id=1949442
    https://lists.debian.org/debian-lts-announce/2021/05/msg00023.html
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3EP2VJ73OVBPVSOSTVOMGIEQA3MWF6F7/
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZAF6L2M6CNAJ2YYYGXPWETTW5YLCWTVT/
    https://security.gentoo.org/glsa/202105-22
    https://security.netapp.com/advisory/ntap-20210430-0001/
    https://www.samba.org/samba/security/CVE-2021-20254.html
    https://bugzilla.redhat.com/show_bug.cgi?id=1949442
    https://lists.debian.org/debian-lts-announce/2021/05/msg00023.html
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3EP2VJ73OVBPVSOSTVOMGIEQA3MWF6F7/
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZAF6L2M6CNAJ2YYYGXPWETTW5YLCWTVT/
    https://security.gentoo.org/glsa/202105-22
    https://security.netapp.com/advisory/ntap-20210430-0001/
    https://www.samba.org/samba/security/CVE-2021-20254.html

    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