oss-sec mailing list archives

CVE Request -- mcrypt: stack-based buffer overflow by encryption / decryption of overly long file names


From: Jan Lieskovsky <jlieskov () redhat com>
Date: Thu, 18 Oct 2012 09:50:37 -0400 (EDT)

Hello Kurt, Steve, vendors,

  Attila Bogar reported a stack-based buffer overflow
in the way MCrypt, a crypt() package and crypt(1) command
replacement, used to encrypt / decrypt files with overly
long names (longer than 128 bytes). A remote attacker
could provide a specially-crafted file that, when processed
by the mcrypt too, would lead to mcrypt executable crash [*].

A different vulnerability than CVE-2012-4409:
[1] https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2012-4409

Note: Using Red Hat bugzilla record for CVE-2012-4409 since
particular Mitre record is not described yet.

References:
[2] https://bugzilla.redhat.com/show_bug.cgi?id=867790

Patch proposed by Attila:
[3] https://bugzilla.redhat.com/show_bug.cgi?id=867790#c0

Reproducer:
To reproduce let mcrypt encrypt / decrypt file with name
longer ~128 bytes.

Could you allocate a CVE id for this?

Thank you && Regards, Jan.
--
Jan iankko Lieskovsky / Red Hat Security Response Team

[*] FORTIFY_SOURCE protection mechanism would mitigate this
deficiency to result into crash only. But on systems, without
FORTIFY_SOURCE protection being applied, the impact might be
higher.

P.S.: I am not sure about relation of this issue to the issue
      Raphael Geissert reported previously:
      [4] http://www.openwall.com/lists/oss-security/2012/10/02/1

      so CC-in him too, he to clarify if [2] == [4], or if
      they are yet different issues. Raphael, please clarify.
      Thanks, Jan.


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