Issued:
2009-08-12
Updated:
2009-08-12

RHSA-2009:1207 - Critical: nspr and nss security update

Synopsis

Critical: nspr and nss security update

Type/Severity

Security Advisory Critical

Topic

Updated nspr and nss packages that fix security issues are now available for Red Hat Enterprise Linux 5.2 Extended Update Support.

This update has been rated as having critical security impact by the Red Hat Security Response Team.

Description

Netscape Portable Runtime (NSPR) provides platform independence for non-GUI operating system facilities. These facilities include threads, thread synchronization, normal file and network I/O, interval timing, calendar time, basic memory management (malloc and free), and shared library linking.

Network Security Services (NSS) is a set of libraries designed to support the cross-platform development of security-enabled client and server applications. Applications built with NSS can support SSLv2, SSLv3, TLS, and other security standards.

These updated packages upgrade NSS from the previous version, 3.12.2, to a prerelease of version 3.12.4. The version of NSPR has also been upgraded from 4.7.3 to 4.7.4.

Moxie Marlinspike reported a heap overflow flaw in a regular expression parser in the NSS library used by browsers such as Mozilla Firefox to match common names in certificates. A malicious website could present a carefully-crafted certificate in such a way as to trigger the heap overflow, leading to a crash or, possibly, arbitrary code execution with the permissions of the user running the browser. (CVE-2009-2404)

Note: in order to exploit this issue without further user interaction in Firefox, the carefully-crafted certificate would need to be signed by a Certificate Authority trusted by Firefox, otherwise Firefox presents the victim with a warning that the certificate is untrusted. Only if the user then accepts the certificate will the overflow take place.

Dan Kaminsky discovered flaws in the way browsers such as Firefox handle NULL characters in a certificate. If an attacker is able to get a carefully-crafted certificate signed by a Certificate Authority trusted by Firefox, the attacker could use the certificate during a man-in-the-middle attack and potentially confuse Firefox into accepting it by mistake. (CVE-2009-2408)

Dan Kaminsky found that browsers still 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. NSS now disables the use of MD2 and MD4 algorithms inside signatures by default. (CVE-2009-2409)

All users of nspr and nss are advised to upgrade to these updated packages, which resolve these issues.

Solution

Before applying this update, make sure that all previously-released errata relevant to your system have been applied.

This update is available via Red Hat Network. Details on how to use the Red Hat Network to apply this update are available at This content is not included.http://kbase.redhat.com/faq/docs/DOC-11259

Affected Products

ProductVersionArch
Red Hat Enterprise Linux for x86_64 - Extended Update Support5.2x86_64
Red Hat Enterprise Linux for x86_64 - Extended Update Support5.2ia64
Red Hat Enterprise Linux for x86_64 - Extended Update Support5.2i386
Red Hat Enterprise Linux for Power, big endian - Extended Update Support5.2ppc
Red Hat Enterprise Linux for IBM z Systems - Extended Update Support5.2s390x

Updated Packages

  • nss-3.12.3.99.3-1.el5_2.s390x.rpm
  • nss-3.12.3.99.3-1.el5_2.s390.rpm
  • nss-tools-3.12.3.99.3-1.el5_2.s390x.rpm
  • nspr-devel-4.7.4-1.el5_2.s390.rpm
  • nss-devel-3.12.3.99.3-1.el5_2.s390.rpm
  • nss-pkcs11-devel-3.12.3.99.3-1.el5_2.s390x.rpm
  • nspr-4.7.4-1.el5_2.s390.rpm
  • nss-pkcs11-devel-3.12.3.99.3-1.el5_2.s390.rpm
  • nss-devel-3.12.3.99.3-1.el5_2.s390x.rpm
  • nspr-devel-4.7.4-1.el5_2.s390x.rpm
  • nspr-4.7.4-1.el5_2.s390x.rpm

Fixes

CVEs

References

Additional information