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6 <title>Samba - Security Announcement Archive</title>
11 <H2>CVE-2018-16841.html:</H2>
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16 == Subject: Double-free in Samba AD DC KDC with PKINIT
18 == CVE ID#: CVE-2018-16841
20 == Versions: All versions of Samba from 4.3.0 onwards.
22 == Summary: A user with a valid certificate or smart card
23 can crash the Samba AD DC's KDC.
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30 When configured to accept smart-card authentication, Samba's KDC will
31 call talloc_free() twice on the same memory if the principal in a
32 validly signed certificate does not match the principal in the AS-REQ.
34 This is only possible after authentication with a trusted certificate.
36 talloc is robust against further corruption from a double-free with
37 talloc_free() and directly calls abort(), terminating the KDC process.
39 There is no further vulnerability associated with this issue, merely a
46 Patches addressing both these issues have been posted to:
48 http://www.samba.org/samba/security/
50 Additionally, Samba 4.7.12, 4.8.7 and 4.9.3 have been issued
51 as security releases to correct the defect. Samba administrators are
52 advised to upgrade to these releases or apply the patch as soon
59 CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H (6.5)
65 Remove 'enable-pkinit = true' from the krb5.conf to disable smart-card
72 Originally reported by Alex MacCuish
74 Patches provided by Andrew Bartlett of the Samba Team and Catalyst.
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77 == Our Code, Our Bugs, Our Responsibility.
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