RHEL 5 : gnutls (RHSA-2010:0166)
Medium Nessus Plugin ID 46277
SynopsisThe remote Red Hat host is missing one or more security updates.
DescriptionUpdated gnutls packages that fix two security issues are now available for Red Hat Enterprise Linux 5.
The Red Hat Security Response Team has rated this update as having moderate security impact. Common Vulnerability Scoring System (CVSS) base scores, which give detailed severity ratings, are available for each vulnerability from the CVE links in the References section.
The GnuTLS library provides support for cryptographic algorithms and for protocols such as Transport Layer Security (TLS).
A flaw was found in the way the TLS/SSL (Transport Layer Security/Secure Sockets Layer) protocols handled session renegotiation. A man-in-the-middle attacker could use this flaw to prefix arbitrary plain text to a client's session (for example, an HTTPS connection to a website). This could force the server to process an attacker's request as if authenticated using the victim's credentials. This update addresses this flaw by implementing the TLS Renegotiation Indication Extension, as defined in RFC 5746.
Refer to the following Knowledgebase article for additional details about the CVE-2009-3555 flaw:
Dan Kaminsky found that browsers could accept certificates with MD2 hash signatures, even though MD2 is no longer considered a cryptographically strong algorithm. This could make it easier for an attacker to create a malicious certificate that would be treated as trusted by a browser. GnuTLS now disables the use of the MD2 algorithm inside signatures by default. (CVE-2009-2409)
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.
SolutionUpdate the affected gnutls, gnutls-devel and / or gnutls-utils packages.