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Debian Security Advisory DSA-3740-1                   [email protected]
https://www.debian.org/security/                     Salvatore Bonaccorso
December 19, 2016                     https://www.debian.org/security/faq
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Package        : samba
CVE ID         : CVE-2016-2119 CVE-2016-2123 CVE-2016-2125 CVE-2016-2126
Debian Bug     : 830195

Several vulnerabilities have been discovered in Samba, a SMB/CIFS file,
print, and login server for Unix. The Common Vulnerabilities and
Exposures project identifies the following issues:


    Stefan Metzmacher discovered that client-side SMB2/3 required
    signing can be downgraded, allowing a man-in-the-middle attacker to
    impersonate a server being connected to by Samba, and return
    malicious results.


    Trend Micro's Zero Day Initiative and Frederic Besler discovered
    that the routine ndr_pull_dnsp_name, used to parse data from the
    Samba Active Directory ldb database, contains an integer overflow
    flaw, leading to an attacker-controlled memory overwrite. An
    authenticated user can take advantage of this flaw for remote
    privilege escalation.


    Simo Sorce of Red Hat discovered that the Samba client code always
    requests a forwardable ticket when using Kerberos authentication. A
    target server, which must be in the current or trusted domain/realm,
    is given a valid general purpose Kerberos "Ticket Granting Ticket"
    (TGT), which can be used to fully impersonate the authenticated user
    or service.


    Volker Lendecke discovered several flaws in the Kerberos PAC
    validation. A remote, authenticated, attacker can cause the winbindd
    process to crash using a legitimate Kerberos ticket due to incorrect
    handling of the PAC checksum. A local service with access to the
    winbindd privileged pipe can cause winbindd to cache elevated access

For the stable distribution (jessie), these problems have been fixed in
version 2:4.2.14+dfsg-0+deb8u2. In addition, this update contains
several changes originally targeted for the upcoming jessie point

We recommend that you upgrade your samba packages.

Further information about Debian Security Advisories, how to apply
these updates to your system and frequently asked questions can be
found at: https://www.debian.org/security/

Mailing list: [email protected]