RHSA-2010:0181 - Security Advisory

Topic

Updated brltty packages that fix one security issue and several bugs are
now available for Red Hat Enterprise Linux 5.

The Red Hat Security Response Team has rated this update as having low
security impact. A Common Vulnerability Scoring System (CVSS) base score,
which gives a detailed severity rating, is available from the CVE link in
the References section.

Description

brltty (Braille TTY) is a background process (daemon) which provides access
to the Linux console (when in text mode) for a blind person using a
refreshable braille display. It drives the braille display, and provides
complete screen review functionality.

It was discovered that a brltty library had an insecure relative RPATH
(runtime library search path) set in the ELF (Executable and Linking
Format) header. A local user able to convince another user to run an
application using brltty in an attacker-controlled directory, could run
arbitrary code with the privileges of the victim. (CVE-2008-3279)

These updated packages also provide fixes for the following bugs:

• the brltty configuration file is documented in the brltty manual page,

but there is no separate manual page for the /etc/brltty.conf configuration
file: running "man brltty.conf" returned "No manual entry for brltty.conf"
rather than opening the brltty manual entry. This update adds brltty.conf.5
as an alias to the brltty manual page. Consequently, running "man
brltty.conf" now opens the manual entry documenting the brltty.conf
specification. (BZ#530554)

• previously, the brltty-pm.conf configuration file was installed in the

/etc/brltty/ directory. This file, which configures Papenmeier Braille
Terminals for use with Red Hat Enterprise Linux, is optional. As well, it
did not come with a corresponding manual page. With this update, the file
has been moved to /usr/share/doc/brltty-3.7.2/BrailleDrivers/Papenmeier/.
This directory also includes a README document that explains the file's
purpose and format. (BZ#530554)

• during the brltty packages installation, the message

Creating screen inspection device /dev/vcsa...done.

was presented at the console. This was inadequate, especially during the
initial install of the system. These updated packages do not send any
message to the console during installation. (BZ#529163)

• although brltty contains ELF objects, the brltty-debuginfo package was

empty. With this update, the -debuginfo package contains valid debugging
information as expected. (BZ#500545)

• the MAX_NR_CONSOLES definition was acquired by brltty by #including

linux/tty.h in Programs/api_client.c. MAX_NR_CONSOLES has since moved to
linux/vt.h but the #include in api_client.c was not updated. Consequently,
brltty could not be built from the source RPM against the Red Hat
Enterprise Linux 5 kernel. This update corrects the #include in
api_client.c to linux/vt.h and brltty now builds from source as expected.
(BZ#456247)

All brltty users are advised to upgrade to these updated packages, which
resolve these issues.

Solution

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

This update is available via the Red Hat Network. Details on how to
use the Red Hat Network to apply this update are available at
http://kbase.redhat.com/faq/docs/DOC-11259

Affected Products

• Red Hat Enterprise Linux Server 5 x86_64
• Red Hat Enterprise Linux Server 5 ia64
• Red Hat Enterprise Linux Server 5 i386
• Red Hat Enterprise Linux Workstation 5 x86_64
• Red Hat Enterprise Linux Workstation 5 i386
• Red Hat Enterprise Linux Desktop 5 x86_64
• Red Hat Enterprise Linux Desktop 5 i386
• Red Hat Enterprise Linux for IBM z Systems 5 s390x
• Red Hat Enterprise Linux for Power, big endian 5 ppc
• Red Hat Enterprise Linux Server from RHUI 5 x86_64
• Red Hat Enterprise Linux Server from RHUI 5 i386

Fixes

• BZ - 456247 - brltty doesn't build with kernel 2.6.18-92.1.1
• BZ - 457942 - CVE-2008-3279 brltty: insecure relative RPATH
• BZ - 500545 - brltty-debuginfo is empty
• BZ - 529163 - Creating screen inspection device /dev/vcsa...done.
• BZ - 530554 - Missing man-pages

CVEs

• CVE-2008-3279

References

• http://www.redhat.com/security/updates/classification/#low