Steve
Henson of the OpenSSL core team identified and prepared fixes for a number of
vulnerabilities in the OpenSSL ASN1 code that were discovered after running a
test suite by British National Infrastructure Security Coordination Centre
(NISCC).
A bug in OpenSSLs SSL/TLS protocol was also identified which
causes OpenSSL to parse a client certificate from an SSL/TLS client when
it should reject it as a protocol error.
The Common Vulnerabilities
and Exposures project identifies the following
problems:
CAN-2003-0543:
Integer overflow in OpenSSL that allows
remote attackers to cause a denial of service (crash) via an SSL client
certificate with certain ASN.1 tag
values.
CAN-2003-0544:
OpenSSL does not properly track the number
of characters in certain ASN.1 inputs, which allows remote attackers to cause
a denial of service (crash) via an SSL client certificate that causes
OpenSSL to read past the end of a buffer when the long form is
used.
CAN-2003-0545:
Double-free vulnerability allows remote
attackers to cause a denial of service (crash) and possibly execute arbitrary
code via an SSL client certificate with a certain invalid ASN.1 encoding.
This bug was only present in OpenSSL 0.9.7 and is listed here only
for reference.
For the stable distribution (woody) this problem has
been fixed in openssl095 version 0.9.5a-6.woody.3.
This package is not
present in the unstable (sid) or testing (sarge) distribution.
We
recommend that you upgrade your libssl095a packages and restart services
using this library. Debian doesn't ship any packages that are linked against
this library.
The following commandline (courtesy of Ray Dassen) produces
a list of names of running processes that have libssl095 mapped into
their memory space: