ctdb, ipa, ldb, libldb, libsmbclient, libtalloc, libtdb, libtevent, libwbclient, openchange, pyldb, pytalloc, python, samba, samba4, tdb security update

CentOS Errata and Security Advisory CESA-2016:0612

Samba is an open-source implementation of the Server Message Block (SMB) protocol and the related Common Internet File System (CIFS) protocol, which allow PC-compatible machines to share files, printers, and various information.

The following packages have been upgraded to a newer upstream version: Samba (4.2.10). Refer to the Release Notes listed in the References section for a complete list of changes.

Security Fix(es):

• Multiple flaws were found in Samba’s DCE/RPC protocol implementation. A remote, authenticated attacker could use these flaws to cause a denial of service against the Samba server (high CPU load or a crash) or, possibly, execute arbitrary code with the permissions of the user running Samba (root). This flaw could also be used to downgrade a secure DCE/RPC connection by a man-in-the-middle attacker taking control of an Active Directory (AD) object and compromising the security of a Samba Active Directory Domain Controller (DC). (CVE-2015-5370)

Note: While Samba packages as shipped in Red Hat Enterprise Linux do not support running Samba as an AD DC, this flaw applies to all roles Samba implements.

• A protocol flaw, publicly referred to as Badlock, was found in the Security Account Manager Remote Protocol (MS-SAMR) and the Local Security Authority (Domain Policy) Remote Protocol (MS-LSAD). Any authenticated DCE/RPC connection that a client initiates against a server could be used by a man-in-the-middle attacker to impersonate the authenticated user against the SAMR or LSA service on the server. As a result, the attacker would be able to get read/write access to the Security Account Manager database, and use this to reveal all passwords or any other potentially sensitive information in that database. (CVE-2016-2118)

• Several flaws were found in Samba’s implementation of NTLMSSP authentication. An unauthenticated, man-in-the-middle attacker could use this flaw to clear the encryption and integrity flags of a connection, causing data to be transmitted in plain text. The attacker could also force the client or server into sending data in plain text even if encryption was explicitly requested for that connection. (CVE-2016-2110)

• It was discovered that Samba configured as a Domain Controller would establish a secure communication channel with a machine using a spoofed computer name. A remote attacker able to observe network traffic could use this flaw to obtain session-related information about the spoofed machine. (CVE-2016-2111)

• It was found that Samba’s LDAP implementation did not enforce integrity protection for LDAP connections. A man-in-the-middle attacker could use this flaw to downgrade LDAP connections to use no integrity protection, allowing them to hijack such connections. (CVE-2016-2112)

• It was found that Samba did not validate SSL/TLS certificates in certain connections. A man-in-the-middle attacker could use this flaw to spoof a Samba server using a specially crafted SSL/TLS certificate. (CVE-2016-2113)

• It was discovered that Samba did not enforce Server Message Block (SMB) signing for clients using the SMB1 protocol. A man-in-the-middle attacker could use this flaw to modify traffic between a client and a server. (CVE-2016-2114)

• It was found that Samba did not enable integrity protection for IPC traffic by default. A man-in-the-middle attacker could use this flaw to view and modify the data sent between a Samba server and a client. (CVE-2016-2115)

Red Hat would like to thank the Samba project for reporting these issues. Upstream acknowledges Jouni Knuutinen (Synopsis) as the original reporter of CVE-2015-5370; and Stefan Metzmacher (SerNet) as the original reporter of CVE-2016-2118, CVE-2016-2110, CVE-2016-2112, CVE-2016-2113, CVE-2016-2114, and CVE-2016-2115.

Merged security bulletin from advisories:
https://lists.centos.org/pipermail/centos-announce/2016-April/083976.html
https://lists.centos.org/pipermail/centos-announce/2016-April/083978.html
https://lists.centos.org/pipermail/centos-announce/2016-April/083979.html
https://lists.centos.org/pipermail/centos-announce/2016-April/083980.html
https://lists.centos.org/pipermail/centos-announce/2016-April/083981.html
https://lists.centos.org/pipermail/centos-announce/2016-April/083982.html
https://lists.centos.org/pipermail/centos-announce/2016-April/083984.html
https://lists.centos.org/pipermail/centos-announce/2016-April/083986.html
https://lists.centos.org/pipermail/centos-announce/2016-April/083987.html
https://lists.centos.org/pipermail/centos-announce/2016-April/083988.html
https://lists.centos.org/pipermail/centos-announce/2016-April/083989.html
https://lists.centos.org/pipermail/centos-announce/2016-April/083990.html
https://lists.centos.org/pipermail/centos-announce/2016-April/083991.html
https://lists.centos.org/pipermail/centos-announce/2016-April/083992.html

Affected packages:
ctdb
ctdb-devel
ctdb-tests
ipa-admintools
ipa-client
ipa-python
ipa-server
ipa-server-dns
ipa-server-selinux
ipa-server-trust-ad
ldb-tools
libldb
libldb-devel
libsmbclient
libsmbclient-devel
libtalloc
libtalloc-devel
libtdb
libtdb-devel
libtevent
libtevent-devel
libwbclient
libwbclient-devel
openchange
openchange-client
openchange-devel
openchange-devel-docs
pyldb
pyldb-devel
pytalloc
pytalloc-devel
python-tdb
python-tevent
samba
samba-client
samba-client-libs
samba-common
samba-common-libs
samba-common-tools
samba-dc
samba-dc-libs
samba-devel
samba-libs
samba-pidl
samba-python
samba-test
samba-test-devel
samba-test-libs
samba-vfs-glusterfs
samba-winbind
samba-winbind-clients
samba-winbind-krb5-locator
samba-winbind-modules
samba4
samba4-client
samba4-common
samba4-dc
samba4-dc-libs
samba4-devel
samba4-libs
samba4-pidl
samba4-python
samba4-test
samba4-winbind
samba4-winbind-clients
samba4-winbind-krb5-locator
tdb-tools

Upstream details at:
https://access.redhat.com/errata/RHSA-2016:0612