oss-sec mailing list archives

Re: Re: CVE request: three issues in libksba


From: Andreas Stieger <astieger () suse com>
Date: Tue, 10 May 2016 14:09:11 +0200

Hello,

On 04/29/2016 06:13 PM, cve-assign () mitre org wrote:
Integer overflow in the DN decoder src/dn.c

http://git.gnupg.org/cgi-bin/gitweb.cgi?p=libksba.git;a=commit;h=243d12fdec66a4360fbb3e307a046b39b5b4ffc3

This might be an error in the original
https://security.gentoo.org/glsa/201604-04 advisory. We did not notice
any obvious relationship between
243d12fdec66a4360fbb3e307a046b39b5b4ffc3 and an integer overflow fix.
The 243d12fdec66a4360fbb3e307a046b39b5b4ffc3 commit message seems to
focus on "read access out of bounds." Also, there is no other recent
commit at
http://git.gnupg.org/cgi-bin/gitweb.cgi?p=libksba.git;a=history;f=src/dn.c
that refers to an integer overflow. Possibly there was an inapplicable
copy-and-paste of "Integer overflow in the" from the previous report
about the BER decoder.

Use CVE-2016-4356 for the 243d12fdec66a4360fbb3e307a046b39b5b4ffc3
issue that is described as "Fix encoding of invalid utf-8 strings in
dn.c" and "read access out of bounds."


There is a follow-up fix in libksba 1.3.4 for this issue:
http://git.gnupg.org/cgi-bin/gitweb.cgi?p=libksba.git;a=commit;h=6be61daac047d8e6aa941eb103f8e71a1d4e3c75

Fix an OOB read access in _ksba_dn_to_str.

* src/dn.c (append_utf8_value): Use a straightforward check to fix an
off-by-one.
--

The old fix for the problem from April 2015 had an off-by-one in the
bad encoding handing.

Fixes-commit: 243d12fdec66a4360fbb3e307a046b39b5b4ffc3
<http://git.gnupg.org/cgi-bin/gitweb.cgi?p=libksba.git;a=object;h=243d12fdec66a4360fbb3e307a046b39b5b4ffc3>
GnuPG-bug-id: 2344
Reported-by: Pascal Cuoq
Signed-off-by: Werner Koch <wk () gnupg org>

Andreas

-- 
Andreas Stieger <astieger () suse com>
Project Manager Security
SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton,
HRB 21284 (AG Nürnberg)



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