| <?xml version="1.0" encoding="UTF-8"?> |
| <!DOCTYPE glsa SYSTEM "http://www.gentoo.org/dtd/glsa.dtd"> |
| <glsa id="201603-04"> |
| <title>FUSE: incorrect filtering of environment variables leading to |
| privilege escalation |
| </title> |
| <synopsis>The fusermount binary in FUSE does not properly clear the |
| environment before invoking mount or umount as root that allows a local |
| user to overwrite arbitrary files. |
| </synopsis> |
| <product type="ebuild">fuse</product> |
| <announced>March 09, 2016</announced> |
| <revised>March 09, 2016: 1</revised> |
| <bug>550152</bug> |
| <access>local</access> |
| <affected> |
| <package name="sys-fs/fuse" auto="yes" arch="*"> |
| <unaffected range="ge">2.9.4</unaffected> |
| <vulnerable range="lt">2.9.4</vulnerable> |
| </package> |
| </affected> |
| <background> |
| <p>FUSE provides an interface for filesystems implemented in userspace.</p> |
| </background> |
| <description> |
| <p>The fusermount binary calls setuid(geteuid()) to reset the RUID when it |
| invokes /bin/mount so that it can use privileged mount options that are |
| normally restricted if RUID != EUID. FUSE does not properly clear |
| environment variables before invoking mount or umount as root allowing |
| this to be passed to operations using elevated privileges such as |
| LIBMOUNT_MTAB that is used by the mount commands debugging feature. |
| </p> |
| </description> |
| <impact type="normal"> |
| <p>The FUSE vulnerability allows a local, unprivileged user to overwrite |
| arbitrary files on the system. |
| </p> |
| </impact> |
| <workaround> |
| <p>There is no known work around at this time.</p> |
| </workaround> |
| <resolution> |
| <p>All FUSE users should upgrade to the latest version:</p> |
| |
| <code> |
| # emerge --sync |
| # emerge --ask --oneshot --verbose ">=sys-fs/fuse-2.9.4" |
| </code> |
| </resolution> |
| <references> |
| <uri link="http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-3202"> |
| CVE-2015-3202 |
| </uri> |
| </references> |
| <metadata tag="requester" timestamp="Wed, 09 Sep 2015 05:09:39 +0000"> |
| BlueKnight |
| </metadata> |
| <metadata tag="submitter" timestamp="Wed, 09 Mar 2016 17:59:40 +0000">b-man</metadata> |
| </glsa> |