Impact of the security bug
By using special crafted S/MIME messages or ECC based OpenPGP data, it
is possible to create a buffer overflow. The bug is not easy to exploit
because there only 80 possible values which can be used to overwrite
memory. However, a denial of service is possible and someone may come
up with other clever attacks. Thus this should be fix.
Affected versions: All Libksba versions < 1.3.2
Background: Yesterday Hanno Böck found an invalid memory access in the
2.1 branch of GnuPG by conveying a malformed OID as part of an ECC key.
It turned out that this bug has also been in libksba ever since and
affects at least gpgsm and dirmngr. The code to convert an OID to its
string representation has an obvious error of not considering an invalid
encoding for arc-2. A first byte of 0x80 can be used to make a value of
less then 80 and we then subtract 80 from it as required by the OID
encoding rules. Due to the use of an unsigned integer this results in a
pretty long value which won't fit anymore into the allocated buffer.
The actual fix for lib Libksba is commit f715b9e.
+*libksba-1.3.2 (25 Nov 2014)
+ 25 Nov 2014; Kristian Fiskerstrand <firstname.lastname@example.org> +libksba-1.3.2.ebuild,
+ Version bump. Security bug #530634. Cleanup old non-stable.
new version uploaded and the changes are trivial enough that upgrading should be trivial, but will wait a little bit before calling for stabilization.
Marking B3 due to the specific nature of the attack despite this package being pulled in by default version of GnuPG.
CVE Request: http://seclists.org/oss-sec/2014/q4/788
Arches, please stabilize
Stable targets: alpha amd64 arm hppa ia64 ppc ppc64 sparc x86
Stable for HPPA.
Maintainer(s), please cleanup.
Security, please vote.
Arches, thank you for your work.
GLSA Vote: No
06 Dec 2014; Kristian Fiskerstrand <email@example.com> -libksba-1.3.0.ebuild:
Cleanup old for security bug #530634
Integer underflow in the ksba_oid_to_str function in Libksba before 1.3.2,
as used in GnuPG, allows remote attackers to cause a denial of service
(crash) via a crafted OID in a (1) S/MIME message or (2) ECC based OpenPGP
data, which triggers a buffer overflow.
GLSA Vote: No
No GLSA - Closing Bug as Resolved