Attachment 15545 Details for Bug 14040 – CVE text with 4.11 and -M single (v3)

CVE text with 4.11 and -M single (v3)

CVE-2019-14847-dirsync-advisory-03.txt (text/plain), 2.39 KB, created by Douglas Bagnall on 2019-10-15 21:46:27 UTC

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Creator: Douglas Bagnall

Created: 2019-10-15 21:46:27 UTC

Size: 2.39 KB

patch

obsolete

>===========================================================
>== Subject:     User with "get changes" permission can
>==              crash AD DC LDAP server via dirsync
>==
>== CVE ID#:     CVE-2019-14847
>==
>== Versions:    Samba 4.0.0 until Samba 4.10.0
>==
>== Summary:     Users with the "get changes" extended access
>==              right can crash the AD DC LDAP server by
>==              requesting an attribute using the range= syntax.
>===========================================================
>
>===========
>Description
>===========
>
>Since Samba 4.0.0 Samba has implemented, in the AD DC, the "dirsync"
>LDAP control specified in MS-ADTS "3.1.1.3.4.1.3
>LDAP_SERVER_DIRSYNC_OID".
>
>However, when combined with the ranged results feature specified in
>MS-ADTS "3.1.1.3.1.3.3 Range Retrieval of Attribute Values" a NULL
>pointer is can be de-referenced.
>
>This is a Denial of Service only, no further escalation of privilege
>is associated with this issue.
>
>Samba 4.11 is not affected as the issue was fixed as a result of
>Coverity static analysis, before the potential for denial of service
>became apparent.
>
>==================
>Patch Availability
>==================
>
>Patches addressing both these issues have been posted to:
>
>    https://www.samba.org/samba/security/
>
>Additionally, Samba 4.9.15 and 4.10.10 have been issued
>as security releases to correct the defect.  Samba administrators are
>advised to upgrade to these releases or apply the patch as soon
>as possible.
>
>==================
>CVSSv3 calculation
>==================
>
>CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H (4.9)
>
>==========================
>Workaround and mitigation. 
>==========================
>
>By default, the supported versions of Samba impacted by this issue run
>using the "standard" process model, which is unaffected.
>
>This is controlled by the -M or --model parameter to the samba binary.
>
>Unsupported Samba versions before Samba 4.7 use a single process for
>the LDAP server, and so are impacted.
>
>Samba 4.8, 4.9 and 4.10 are impacted if -M prefork or -M single is
>used. To mitigate this issue, select -M standard (the default).
>
>=======
>Credits
>=======
>
>Originally reported by Adam Xu
>
>Patches provided and advisory written by Douglas Bagnall and Andrew
>Bartlett of the Samba team and Catalyst.
>
>==========================================================
>== Our Code, Our Bugs, Our Responsibility.
>== The Samba Team
>==========================================================
>

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