RHSA-2005:074 - Security Advisory

Topic

Updated rsh packages that fix various bugs and a theoretical security issue
are now available.

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

Description

The rsh package contains a set of programs that allow users to run
commands on remote machines, login to other machines, and copy files
between machines, using the rsh, rlogin, and rcp commands. All three of
these commands use rhosts-style authentication.

The rcp protocol allows a server to instruct a client to write to arbitrary
files outside of the current directory. This could potentially cause a
security issue if a user uses rcp to copy files from a malicious server.
The Common Vulnerabilities and Exposures project (cve.mitre.org) has
assigned the name CAN-2004-0175 to this issue.

These updated packages also address the following bugs:

The rexec command failed with "Invalid Argument", because the code
used sigaction() as an unsupported signal.

The rlogind server reported "SIGCHLD set to SIG_IGN but calls wait()"
message to the system log because the original BSD code was ported
incorrectly to linux.

The rexecd server did not function on systems where client hostnames were
not in the DNS service, because server code called gethostbyaddr() for each
new connection.

The rcp command incorrectly used the "errno" variable and produced
erroneous error messages.

The rexecd command ignored settings in the /etc/security/limits file,
because the PAM session was incorrectly initialized.

The rexec command prompted for username and password regardless of the
~/.netrc configuration file contents. This updated package contains a patch
that no longer skips the ~/.netrc file.

All users of rsh should 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.

To update all RPMs for your particular architecture, run:

rpm -Fvh [filenames]

where [filenames] is a list of the RPMs you wish to upgrade. Only those
RPMs which are currently installed will be updated. Those RPMs which are
not installed but included in the list will not be updated. Note that you
can also use wildcards (*.rpm) if your current directory *only* contains the
desired RPMs.

Please note that this update is also available via Red Hat Network. Many
people find this an easier way to apply updates. To use Red Hat Network,
launch the Red Hat Update Agent with the following command:

up2date

This will start an interactive process that will result in the appropriate
RPMs being upgraded on your system.

If up2date fails to connect to Red Hat Network due to SSL
Certificate Errors, you need to install a version of the
up2date client with an updated certificate. The latest version of
up2date is available from the Red Hat FTP site and may also be
downloaded directly from the RHN website:

https://rhn.redhat.com/help/latest-up2date.pxt

Affected Products

• Red Hat Enterprise Linux Server 3 x86_64
• Red Hat Enterprise Linux Server 3 ia64
• Red Hat Enterprise Linux Server 3 i386
• Red Hat Enterprise Linux Workstation 3 x86_64
• Red Hat Enterprise Linux Workstation 3 ia64
• Red Hat Enterprise Linux Workstation 3 i386
• Red Hat Enterprise Linux Desktop 3 x86_64
• Red Hat Enterprise Linux Desktop 3 i386
• Red Hat Enterprise Linux for IBM z Systems 3 s390x
• Red Hat Enterprise Linux for IBM z Systems 3 s390
• Red Hat Enterprise Linux for Power, big endian 3 ppc

Fixes

• BZ - 67361 - rcp gives incorrect error report when file system writes fai
• BZ - 118630 - rexec fails with "Invalid Argument"
• BZ - 146435 - RHEL3: rexec prompts for username/password before checking ~/.netrc
• BZ - 146437 - RHEL3: rexecd does not set limits on /etc/security/limits
• BZ - 146464 - malicious rsh server can cause rcp to write to arbitrary files (like scp CAN-2004-0175)

CVEs

• CVE-2004-0175

References

(none)