rsync is a file transfer program to keep remote directories synchronized.
Sebastian Krahmer of SUSE reported an integer overflow in the expand_item_list() function in the file util.c which might lead to a heap-based buffer overflow when extended attribute (xattr) support is enabled.
A remote attacker could send a file containing specially crafted extended attributes to an rsync deamon, or entice a user to sync from an rsync server containing specially crafted files, possibly leading to the execution of arbitrary code.
Please note that extended attributes are only enabled when USE="acl" is enabled, which is the default setting.
Disable extended attributes in the rsync daemon by setting "refuse options = xattrs" in the file "/etc/rsyncd.conf" (or append "xattrs" to an existing "refuse" statement). When synchronizing to a server, do not provide the "-X" parameter to rsync. You can also disable the "acl" USE flag for rsync and recompile the package.
All rsync users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=net-misc/rsync-2.6.9-r6"