4.49. gnutls

Updated gnutls packages that fix one bug are now available for Red Hat Enterprise Linux 5.
The gnutls package provides the GNU Transport Layer Security (GnuTLS) library, which provides a secure layer over a transport layer using protocols such as TLS, SSL and DTLS.

Bug Fix

BZ#789041
Under certain circumstances, a NULL pointer could have been dereferenced in the GnuTLS library. This caused TLS clients, such as the rsyslog utility, to terminate unexpectedly with a segmentation fault. This update adds a test condition ensuring that a NULL pointer can no longer be dereferenced and TLS clients no longer crash.
All users of gnutls are advised to upgrade to these updated packages, which fix this bug. All applications linked with the GnuTLS library must be restarted (or the system rebooted) in order for this update to take effect.
Updated gnutls packages that fix three bugs are now available for Red Hat Enterprise Linux 5.
The gnutls packages provides the GNU Transport Layer Security (GnuTLS) library, which provides a secure layer over a transport layer using protocols such as TLS, SSL, and DTLS.

Bug Fixes

BZ#592112
The gnutls packages reported wrong distinguished names (DNs) for chain CA certificates used for the client authentication; the issuer DN was reported instead of the subject DN. As a consequence, the TLS clients were not able to provide a client certificate signed by a chain CA certificate when connecting to a gnutls TLS server. The underlying source code has been modified and gnutls now reports the right DN and the TLS clients work as expected in the described scenario.
BZ#730816
Previously, in the certool utility was a missing check used for an empty string when a challenge password was entered. Consequently, certificate requests generated by certtool were sometimes invalid when an empty challenge password was used. This missing empty-string check has been added and now the certtool's certificate requests are valid even if the challenge password is not entered.
BZ#785001
Under certain circumstances, a null pointer could be dereferenced in the GnuTLS library. This caused TLS clients, such as the rsyslog utility, to terminate unexpectedly with a segmentation fault. This update adds a test condition ensuring that null pointers can no longer be dereferenced and TLS clients no longer crash.
All users of gnutls are advised to upgrade to these updated packages, which fix these bugs.
Updated gnutls packages that fix three security issues are now available for Red Hat Enterprise Linux 5.
The Red Hat Security Response Team has rated this update as having important security impact. Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) associated with each description below.
The GnuTLS library provides support for cryptographic algorithms and for protocols such as Transport Layer Security (TLS). GnuTLS includes libtasn1, a library developed for ASN.1 (Abstract Syntax Notation One) structures management that includes DER (Distinguished Encoding Rules) encoding and decoding.

Security Fixes

CVE-2012-1573
A flaw was found in the way GnuTLS decrypted malformed TLS records. This could cause a TLS/SSL client or server to crash when processing a specially-crafted TLS record from a remote TLS/SSL connection peer.
CVE-2012-1569
A flaw was found in the way libtasn1 decoded DER data. An attacker could create a carefully-crafted X.509 certificate that, when parsed by an application that uses GnuTLS, could cause the application to crash.
CVE-2011-4128
A boundary error was found in the gnutls_session_get_data() function. A malicious TLS/SSL server could use this flaw to crash a TLS/SSL client or, possibly, execute arbitrary code as the client, if the client passed a fixed-sized buffer to gnutls_session_get_data() before checking the real size of the session data provided by the server.
Red Hat would like to thank Matthew Hall of Mu Dynamics for reporting CVE-2012-1573 and CVE-2012-1569.
Users of GnuTLS are advised to upgrade to these updated packages, which contain backported patches to correct these issues. For the update to take effect, all applications linked to the GnuTLS library must be restarted, or the system rebooted.