Bug 532940 (CVE-2010-0788)
| Summary: | CVE-2010-0788 ncpfs: Race condition by mount (ncpmount) / umount (ncpumount) operations | ||||||
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| Product: | [Other] Security Response | Reporter: | Jan Lieskovsky <jlieskov> | ||||
| Component: | vulnerability | Assignee: | Red Hat Product Security <security-response-team> | ||||
| Status: | CLOSED ERRATA | QA Contact: | |||||
| Severity: | low | Docs Contact: | |||||
| Priority: | low | ||||||
| Version: | unspecified | CC: | gdeschner, jbacik, jlayton, kreilly, lemenkov, mjc, security-response-team, ssorce, vcrhonek, vdanen | ||||
| Target Milestone: | --- | Keywords: | Security | ||||
| Target Release: | --- | ||||||
| Hardware: | All | ||||||
| OS: | Linux | ||||||
| Whiteboard: | |||||||
| Fixed In Version: | Doc Type: | Bug Fix | |||||
| Doc Text: | Story Points: | --- | |||||
| Clone Of: | |||||||
| : | CVE-2010-0787 CVE-2010-0789 (view as bug list) | Environment: | |||||
| Last Closed: | 2010-03-26 16:02:33 UTC | Type: | --- | ||||
| Regression: | --- | Mount Type: | --- | ||||
| Documentation: | --- | CRM: | |||||
| Verified Versions: | Category: | --- | |||||
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |||||
| Cloudforms Team: | --- | Target Upstream Version: | |||||
| Embargoed: | |||||||
| Bug Depends On: | 558826 | ||||||
| Bug Blocks: | |||||||
| Attachments: |
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Vulnerable package versions: a, samba-client (mount.cifs) This issue affects the versions of the samba-client package, as shipped with Red Hat Enterprise Linux 4 and 5. Though the "mount.cifs" binary on these systems is NOT shipped with setuid root bit enabled by default (unprivileged user is NOT able to mount custom CIFS shares), which mitigates the impact of the vulnerability. This issue affects the versions of the samba-client package, as shipped with Fedora 11 and 12. "mount.cifs" binary is NOT shipped with setuid root bit enabled on these systems. b, fuse (fusermount -u) This issue affects the version of the "fuse" package, as shipped with Red Hat Enterprise Linux 5. "fusermount" binary IS shipped with setuid root bit enabled on Red Hat Enteprise Linux 5, but unprivileged user, to be able to mount custom FUSE filesystem shares, need first to be member of special "fuse" group (privilege provided by the privileged user), which mitigates the impact of this vulnerability. This issue affects the versions of the "fuse" package, as shipped with Fedora release of 11 and 12. c, ncpfs (ncpmount, ncpumount) These issues affect the versions of the ncpfs package, as shipped with Fedora release of 11 and 12. The "ncpmount / ncpumount" binaries are NOT shipped with setuid root bit enabled by default (unprivileged user is NOT able to mount / umount custom remote NCP protocol shares), which mitigates the impact of the vulnerability. ncpfs-2.2.6-13.fc12 has been submitted as an update for Fedora 12. http://admin.fedoraproject.org/updates/ncpfs-2.2.6-13.fc12 ncpfs-2.2.6-12.fc11 has been submitted as an update for Fedora 11. http://admin.fedoraproject.org/updates/ncpfs-2.2.6-12.fc11 samba-3.4.5-55.fc12 has been submitted as an update for Fedora 12. http://admin.fedoraproject.org/updates/samba-3.4.5-55.fc12 samba-3.4.5-0.47.fc11 has been submitted as an update for Fedora 11. http://admin.fedoraproject.org/updates/samba-3.4.5-0.47.fc11 ncpfs-2.2.6-13.fc12 has been pushed to the Fedora 12 stable repository. If problems still persist, please make note of it in this bug report. ncpfs-2.2.6-12.fc11 has been pushed to the Fedora 11 stable repository. If problems still persist, please make note of it in this bug report. samba-3.4.5-0.47.fc11 has been pushed to the Fedora 11 stable repository. If problems still persist, please make note of it in this bug report. samba-3.4.5-55.fc12 has been pushed to the Fedora 12 stable repository. If problems still persist, please make note of it in this bug report. fuse-2.8.1-2.fc11 has been pushed to the Fedora 11 stable repository. If problems still persist, please make note of it in this bug report. fuse-2.8.1-4.fc12 has been pushed to the Fedora 12 stable repository. If problems still persist, please make note of it in this bug report. MITRE has rejected the use of CVE-2009-3297 because it was used for samba, ncpfs, and fuse when it should only have been used for Samba. Instead, new CVEs have been assigned as follows: CVE-2010-0787: samba CVE-2010-0788: ncpfs CVE-2010-0789: fuse For Samba: This issue does not affect Red Hat Enterprise Linux 4 and 5 by default as mount.cifs is not provided with the setuid bit enabled. If a user has turned on the setuid bit (via 'chmod +s /sbin/mount.cifs'), they would be affected by this issue and can workaround the problem by removing the setuid bit. Red Hat Enterprise Linux 3 does not provide the mount.cifs program. For FUSE: This issue does affect Red Hat Enterprise Linux 5 because it does ship fusermount suid root, however the impact of this flaw is minimized due to the fact that only members in group 'fuse' may use it; the executable is owned root:fuse and mode 4750. Red Hat Enterprise Linux 3 and 4 do not provide the fuse package. The Red Hat Security Response Team has rated this issue as having low security impact, a future update may address this flaw. More information regarding issue severity can be found here: http://www.redhat.com/security/updates/classification/ This bug has been split out so that each CVE has its own bug. Please see: https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2010-0787 for Samba and https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2010-0789 for fuse As updated packages for ncpfs have been pushed for Fedora, this bug is resolved. |
Several race condition flaws were found in samba-client, fuse and ncpfs packages: a, Ronald Volgers found a race condition in the samba-client's mount.cifs utility. Local, unprivileged user could use this flaw to conduct symlink attacks, leading to disclosure of sensitive information, or, possibly to privilege escalation. Upstream bug report: https://bugzilla.samba.org/show_bug.cgi?id=6853 Upstream Samba patches: http://git.samba.org/?p=samba.git;a=commit;h=3ae5dac462c4ed0fb2cd94553583c56fce2f9d80 http://git.samba.org/?p=samba.git;a=commit;h=a065c177dfc8f968775593ba00dffafeebb2e054 http://git.samba.org/?p=samba.git;a=commit;h=a0c31ec1c8d1220a5884e40d9ba6b191a04a24d5 Issue severity note for Red Hat Enteprise Linux: ------------------------------------------------ The mount.cifs binary, as shipped within samba-client package on Red Hat Enterprise Linux 4 and 5, is NOT shipped with setuid root bit enabled by default (local, unprivileged users on these systems are NOT able to mount custom CIFS filesystem shares), which mitigates the impact of the vulnera- bility. b, Dan Rosenberg found a race condition in the FUSE's fusermount's utility by performing FUSE filesystem(s) unmount operation (it was not performed atomically). A local, unprivileged user could use this flaw to cause a denial of service (unprivileged unmount of FUSE filesystem share(s) owned by privileged user) via symlink attack involving FUSE share(s) belonging to privileged user. Issue severity note for Red Hat Enterprise Linux: ------------------------------------------------- The "fusermount" utility, as shipped within "fuse" package in Red Hat Enterprise Linux 5 IS shipped with setuid root bit enabled by default, but the unprivileged user to be able to mount custom FUSE filesystem, he needs prior to be the member of special "fuse" users group (user membership in this group is granted by privileged user), which mitigates the impact of the vulnerability. c, Dan Rosenberg found race conditions in the ncpfs ncpmount and ncpumount utilities. Local, unprivileged user could use these flaws to conduct symlink attacks, leading to denial of service (ncpumount), disclosure of sensitive information, or, possibly to privilege escalation (ncpmount). Issue severity note for Fedora: ------------------------------- The "ncpmount and ncpumount" utilities, as shipped within "ncpfs" package in Fedora release of 11 and 12 are NOT shipped with setuid root bit enabled by default (unprivileged, local users are NOT able to mount / umount custom remote NCP shares), which mitigates the impact of the flaws. Acknowledgements: Red Hat would like to thank Dan Rosenberg for responsibly reporting these flaws.