A file existence dislosure flaw was found in the way mount.cifs tool of the Samba SMB/CIFS tools suite performed mount of a Linux CIFS (Common Internet File System) filesystem. A local user, able to mount a remote CIFS share / target to a local directory could use this flaw to confirm (non) existence of a file system object (file, directory or process descriptor) via error messages generated during the mount.cifs tool run.
Upstream bug report:
It's not clear to me what the proposed remedy is. Should we just not print
the reason for the chdir() failure?
Assigned CVE as per http://www.openwall.com/lists/oss-security/2012/03/27/6
Note too that this is not a real issue for RHEL as we have (quite wisely)
never shipped mount.cifs as a setuid binary. Customers may change the
perms on it after the fact, but it's not a problem in the default configuration.
Once we have a fix upstream, we may as well take it for RHEL, but I don't
think it's urgent.
Patch sent upstream. I plan to wait 2-3 days and then commit it if no one comments.
Created cifs-utils tracking bugs for this issue
Affects: fedora-all [bug 812783]
This issue affects the version of samba/samba3x as shipped with Red Hat Enterprise 5 and the version of cifs-utils as shipped with Red Hat Enterprise Linux 6.
mount.cifs has been the subject of many "security" bugs that have arisen because of users and distributions installing it as a setuid root program.
mount.cifs has not been audited for security. Thus, we strongly recommend that it not be installed setuid root.
The version of mount.cifs in Red Hat Enterprise Linux 6, has an improved code quality, as compared with the version in Red Hat Enterprise Linux 5, making it relatively safer (but still very risky) to use it as a setuid root program.
This issue affects the version of samba/samba3x as shipped with Red Hat Enterprise Linux 5. This issue is not currently planned to be addressed in future updates.
cifs-utils-5.4-1.fc15 has been pushed to the Fedora 15 stable repository. If problems still persist, please make note of it in this bug report.
cifs-utils-5.4-1.fc16 has been pushed to the Fedora 16 stable repository. If problems still persist, please make note of it in this bug report.
cifs-utils-5.4-1.fc17 has been pushed to the Fedora 17 stable repository. If problems still persist, please make note of it in this bug report.
This issue has been addressed in following products:
Red Hat Enterprise Linux 6
Via RHSA-2012:0902 https://rhn.redhat.com/errata/RHSA-2012-0902.html