A pointer use-after-free flaw was found in the OpenSSL's Datagram TLS (DTLS)
implementation. An attacker could use this flaw to cause a denial of
service (s_client crash) by establishing a fake OpenSSL's s_server with
a specially-crafted X509.v3 certificate file.
Credit: Daniel Mentz
Created attachment 344670 [details]
Sample X509v3 certificate used by the s_server proving presence of the flaw
Created attachment 344671 [details]
Patch proposed by the reporter
Scenario (from the openssl-devel report):
When I run
./openssl s_server -dtls1 -no_ecdhe -timeout -cert large.pem
./openssl s_client -dtls1
I'll get a Segmentation fault on the client side.
Use-after-free vulnerability in the dtls1_retrieve_buffered_fragment
function in ssl/d1_both.c in OpenSSL 1.0.0 Beta 2 allows remote
attackers to cause a denial of service (openssl s_client crash) and
possibly have unspecified other impact via a DTLS packet, as
demonstrated by a packet from a server that uses a crafted server
openssl-0.9.8g-14.fc10 has been submitted as an update for Fedora 10.
openssl-0.9.8g-9.14.fc9 has been submitted as an update for Fedora 9.
openssl-0.9.8k-5.fc11 has been submitted as an update for Fedora 11.
This issue did not affect versions of openssl as shipped in Red Hat Enterprise Linux 3 and 4.
This issue affects openssl version as shipped in Red Hat Enterprise Linux 5 and it will be addressed in the openssl packages update in Red Hat Enterprise Linux 5.4. There is no update planned before than, as both DTLS specification and OpenSSL's implementation is still in development and unlikely to be used in production environments. There is no component shipped in Red Hat Enterprise Linux 5 using OpenSSL's DTLS implementation, except for OpenSSL's testing command line client - openssl.
openssl-0.9.8g-14.fc10 has been pushed to the Fedora 10 stable repository. If problems still persist, please make note of it in this bug report.
openssl-0.9.8g-9.14.fc9 has been pushed to the Fedora 9 stable repository. If problems still persist, please make note of it in this bug report.
openssl-0.9.8k-5.fc11 has been pushed to the Fedora 11 stable repository. If problems still persist, please make note of it in this bug report.
This issue has been addressed in following products:
Red Hat Enterprise Linux 5
Via RHSA-2009:1335 https://rhn.redhat.com/errata/RHSA-2009-1335.html