RHSA-2011:0999 - Security Advisory

Topic

An updated rsync package that fixes one security issue, several bugs, and
adds enhancements is now available for Red Hat Enterprise Linux 5.

The Red Hat Security Response Team has rated this update as having moderate
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

rsync is a program for synchronizing files over a network.

A flaw was found in the way the rsync daemon handled the "filter",
"exclude", and "exclude from" options, used for hiding files and preventing
access to them from rsync clients. A remote attacker could use this flaw to
bypass those restrictions by using certain command line options and
symbolic links, allowing the attacker to overwrite those files if they knew
their file names and had write access to them. (CVE-2007-6200)

Note: This issue only affected users running rsync as a writable daemon:
"read only" set to "false" in the rsync configuration file (for example,
"/etc/rsyncd.conf"). By default, this option is set to "true".

This update also fixes the following bugs:

• The rsync package has been upgraded to upstream version 3.0.6, which

provides a number of bug fixes and enhancements over the previous version.
(BZ#339971)

• When running an rsync daemon that was receiving files, a deferred info,

error or log message could have been sent directly to the sender instead of
being handled by the "rwrite()" function in the generator. Also, under
certain circumstances, a deferred info or error message from the receiver
could have bypassed the log file and could have been sent only to the
client process. As a result, an "unexpected tag 3" fatal error could have
been displayed. These problems have been fixed in this update so that an
rsync daemon receiving files now works as expected. (BZ#471182)

• Prior to this update, the rsync daemon called a number of timezone-using

functions after doing a chroot. As a result, certain C libraries were
unable to generate proper timestamps from inside a chrooted daemon. This
bug has been fixed in this update so that the rsync daemon now calls the
respective timezone-using functions prior to doing a chroot, and proper
timestamps are now generated as expected. (BZ#575022)

• When running rsync under a non-root user with the "-A" ("--acls") option

and without using the "--numeric-ids" option, if there was an Access
Control List (ACL) that included a group entry for a group that the
respective user was not a member of on the receiving side, the
"acl_set_file()" function returned an invalid argument value ("EINVAL").
This was caused by rsync mistakenly mapping the group name to the Group ID
"GID_NONE" ("-1"), which failed. The bug has been fixed in this update so
that no invalid argument is returned and rsync works as expected.
(BZ#616093)

• When creating a sparse file that was zero blocks long, the "rsync
• -sparse" command did not properly truncate the sparse file at the end of

the copy transaction. As a result, the file size was bigger than expected.
This bug has been fixed in this update by properly truncating the file so
that rsync now copies such files as expected. (BZ#530866)

• Under certain circumstances, when using rsync in daemon mode, rsync

generator instances could have entered an infinitive loop, trying to write
an error message for the receiver to an invalid socket. This problem has
been fixed in this update by adding a new sibling message: when the
receiver is reporting a socket-read error, the generator will notice this
fact and avoid writing an error message down the socket, allowing it to
close down gracefully when the pipe from the receiver closes. (BZ#690148)

• Prior to this update, there were missing deallocations found in the

"start_client()" function. This bug has been fixed in this update and no
longer occurs. (BZ#700450)

All users of rsync are advised to upgrade to this updated package, which
resolves these issues and adds enhancements.

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
https://access.redhat.com/kb/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 - 339971 - [RFE] Rebase rsync packages to version 3
• BZ - 407171 - CVE-2007-6200 rsync excluded content access restrictions bypass via symlinks
• BZ - 471182 - rsync errors: unexpected tag 3 [sender]
• BZ - 530866 - rsync --sparse does not properly copy sparse files
• BZ - 575022 - rsyncd gets confused with timezones when logging to syslog
• BZ - 616093 - EINVAL (Invalid argument) setting group --acls
• BZ - 690148 - Rsync instances stay in memory when using in daemon mode
• BZ - 700450 - Resource leaks revealed by Coverity scan.

CVEs

• CVE-2007-6200

References

• https://access.redhat.com/security/updates/classification/#moderate
• http://rsync.samba.org/security.html#s3_0_0