# CVE-2018-16851: ctdb: Samba from version 4.0.0 and before versions 4.7.12, 4.8.7, 4.9.3 is vulnerable to a denial of service CVE-2018-16851 is fixed in 17 products on 1 platform, first by ctdb 2:4.7.6+dfsg~ubuntu-0ubuntu2.5, released November 26, 2018. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2018-16851 - Priority: Routine - CVSS: n/a (Medium) - EPSS: 0.0325 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Nov 26, 2018 ## Description Samba from version 4.0.0 and before versions 4.7.12, 4.8.7, 4.9.3 is vulnerable to a denial of service. During the processing of an LDAP search before Samba's AD DC returns the LDAP entries to the client, the entries are cached in a single memory object with a maximum size of 256MB. When this size is reached, the Samba process providing the LDAP service will follow the NULL pointer, terminating the process. There is no further vulnerability associated with this issue, merely a denial of service. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | ctdb Ubuntu 18.04.6 LTS (bionic) | 2:4.7.6+dfsg~ubuntu-0ubuntu2.5 | [ctdb 2:4.7.6+dfsg~ubuntu-0ubuntu2.5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-ctdb-2-4.7.6-dfsg-ubuntu-0ubuntu2.5.md) | Nov 26, 2018 | | Linux | libnss-winbind Ubuntu 18.04.6 LTS (bionic) | 2:4.7.6+dfsg~ubuntu-0ubuntu2.5 | [libnss-winbind 2:4.7.6+dfsg~ubuntu-0ubuntu2.5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libnss-winbind-2-4.7.6-dfsg-ubuntu-0ubuntu2.5.md) | Nov 26, 2018 | | Linux | libpam-winbind Ubuntu 18.04.6 LTS (bionic) | 2:4.7.6+dfsg~ubuntu-0ubuntu2.5 | [libpam-winbind 2:4.7.6+dfsg~ubuntu-0ubuntu2.5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libpam-winbind-2-4.7.6-dfsg-ubuntu-0ubuntu2.5.md) | Nov 26, 2018 | | Linux | libparse-pidl-perl Ubuntu 18.04.6 LTS (bionic) | 2:4.7.6+dfsg~ubuntu-0ubuntu2.5 | [libparse-pidl-perl 2:4.7.6+dfsg~ubuntu-0ubuntu2.5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libparse-pidl-perl-2-4.7.6-dfsg-ubuntu-0ubuntu2.5.md) | Nov 26, 2018 | | Linux | libsmbclient Ubuntu 18.04.6 LTS (bionic) | 2:4.7.6+dfsg~ubuntu-0ubuntu2.5 | [libsmbclient 2:4.7.6+dfsg~ubuntu-0ubuntu2.5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libsmbclient-2-4.7.6-dfsg-ubuntu-0ubuntu2.5.md) | Nov 26, 2018 | | Linux | libwbclient0 Ubuntu 18.04.6 LTS (bionic) | 2:4.7.6+dfsg~ubuntu-0ubuntu2.5 | [libwbclient0 2:4.7.6+dfsg~ubuntu-0ubuntu2.5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libwbclient0-2-4.7.6-dfsg-ubuntu-0ubuntu2.5.md) | Nov 26, 2018 | | Linux | python-samba Ubuntu 18.04.6 LTS (bionic) | 2:4.7.6+dfsg~ubuntu-0ubuntu2.5 | [python-samba 2:4.7.6+dfsg~ubuntu-0ubuntu2.5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-python-samba-2-4.7.6-dfsg-ubuntu-0ubuntu2.5.md) | Nov 26, 2018 | | Linux | registry-tools Ubuntu 18.04.6 LTS (bionic) | 2:4.7.6+dfsg~ubuntu-0ubuntu2.5 | [registry-tools 2:4.7.6+dfsg~ubuntu-0ubuntu2.5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-registry-tools-2-4.7.6-dfsg-ubuntu-0ubuntu2.5.md) | Nov 26, 2018 | | Linux | samba Ubuntu 18.04.6 LTS (bionic) | 2:4.7.6+dfsg~ubuntu-0ubuntu2.5 | [samba 2:4.7.6+dfsg~ubuntu-0ubuntu2.5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-samba-2-4.7.6-dfsg-ubuntu-0ubuntu2.5.md) | Nov 26, 2018 | | Linux | samba-common Ubuntu 18.04.6 LTS (bionic) | 2:4.7.6+dfsg~ubuntu-0ubuntu2.5 | [samba-common 2:4.7.6+dfsg~ubuntu-0ubuntu2.5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-samba-common-2-4.7.6-dfsg-ubuntu-0ubuntu2.5.md) | Nov 26, 2018 | | Linux | samba-common-bin Ubuntu 18.04.6 LTS (bionic) | 2:4.7.6+dfsg~ubuntu-0ubuntu2.5 | [samba-common-bin 2:4.7.6+dfsg~ubuntu-0ubuntu2.5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-samba-common-bin-2-4.7.6-dfsg-ubuntu-0ubuntu2.5.md) | Nov 26, 2018 | | Linux | samba-dsdb-modules Ubuntu 18.04.6 LTS (bionic) | 2:4.7.6+dfsg~ubuntu-0ubuntu2.5 | [samba-dsdb-modules 2:4.7.6+dfsg~ubuntu-0ubuntu2.5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-samba-dsdb-modules-2-4.7.6-dfsg-ubuntu-0ubuntu2.5.md) | Nov 26, 2018 | | Linux | samba-libs Ubuntu 18.04.6 LTS (bionic) | 2:4.7.6+dfsg~ubuntu-0ubuntu2.5 | [samba-libs 2:4.7.6+dfsg~ubuntu-0ubuntu2.5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-samba-libs-2-4.7.6-dfsg-ubuntu-0ubuntu2.5.md) | Nov 26, 2018 | | Linux | samba-testsuite Ubuntu 18.04.6 LTS (bionic) | 2:4.7.6+dfsg~ubuntu-0ubuntu2.5 | [samba-testsuite 2:4.7.6+dfsg~ubuntu-0ubuntu2.5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-samba-testsuite-2-4.7.6-dfsg-ubuntu-0ubuntu2.5.md) | Nov 26, 2018 | | Linux | samba-vfs-modules Ubuntu 18.04.6 LTS (bionic) | 2:4.7.6+dfsg~ubuntu-0ubuntu2.5 | [samba-vfs-modules 2:4.7.6+dfsg~ubuntu-0ubuntu2.5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-samba-vfs-modules-2-4.7.6-dfsg-ubuntu-0ubuntu2.5.md) | Nov 26, 2018 | | Linux | smbclient Ubuntu 18.04.6 LTS (bionic) | 2:4.7.6+dfsg~ubuntu-0ubuntu2.5 | [smbclient 2:4.7.6+dfsg~ubuntu-0ubuntu2.5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-smbclient-2-4.7.6-dfsg-ubuntu-0ubuntu2.5.md) | Nov 26, 2018 | | Linux | winbind Ubuntu 18.04.6 LTS (bionic) | 2:4.7.6+dfsg~ubuntu-0ubuntu2.5 | [winbind 2:4.7.6+dfsg~ubuntu-0ubuntu2.5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-winbind-2-4.7.6-dfsg-ubuntu-0ubuntu2.5.md) | Nov 26, 2018 | --- Data as of 2026-11-08T00:53:09Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.