Samba 4.8.7 (gzipped)
Signature
Patch (gzipped) against Samba 4.8.6
Signature
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Release Notes for Samba 4.8.7
November 27, 2018
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This is a security release in order to address the following defects:
o CVE-2018-14629 (Unprivileged adding of CNAME record causing loop in AD
Internal DNS server)
o CVE-2018-16841 (Double-free in Samba AD DC KDC with PKINIT)
o CVE-2018-16851 (NULL pointer de-reference in Samba AD DC LDAP server)
o CVE-2018-16853 (Samba AD DC S4U2Self crash in experimental MIT Kerberos
configuration (unsupported))
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Details
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o CVE-2018-14629:
All versions of Samba from 4.0.0 onwards are vulnerable to infinite
query recursion caused by CNAME loops. Any dns record can be added via
ldap by an unprivileged user using the ldbadd tool, so this is a
security issue.
o CVE-2018-16841:
When configured to accept smart-card authentication, Samba's KDC will call
talloc_free() twice on the same memory if the principal in a validly signed
certificate does not match the principal in the AS-REQ.
This is only possible after authentication with a trusted certificate.
talloc is robust against further corruption from a double-free with
talloc_free() and directly calls abort(), terminating the KDC process.
There is no further vulnerability associated with this issue, merely a
denial of service.
o CVE-2018-16851:
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.
o CVE-2018-16853:
A user in a Samba AD domain can crash the KDC when Samba is built in the
non-default MIT Kerberos configuration.
With this advisory we clarify that the MIT Kerberos build of the Samba
AD DC is considered experimental. Therefore the Samba Team will not
issue security patches for this configuration.
For more details and workarounds, please refer to the security advisories.
Changes since 4.8.6:
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o Andrew Bartlett <abartlet@samba.org>
* BUG 13628: CVE-2018-16841: heimdal: Fix segfault on PKINIT with
mis-matching principal.
* BUG 13678: CVE-2018-16853: build: The Samba AD DC, when build with MIT
Kerberos is experimental
o Aaron Haslett <aaronhaslett@catalyst.net.nz>
* BUG 13600: CVE-2018-14629: dns: CNAME loop prevention using counter.
o Garming Sam <garming@catalyst.net.nz>
* BUG 13674: CVE-2018-16851: ldap_server: Check ret before manipulating blob.