Details
David Watson discovered that “umount -r” removed some restrictive
mount options like the “nosuid” flag. If /etc/fstab contains
user-mountable removable devices which specify the “nosuid” flag
(which is common practice for such devices), a local attacker could
exploit this to execute arbitrary programs with root privileges by
calling “umount -r” on a removable device.
This does not affect the default Ubuntu configuration. Since Ubuntu
mounts removable devices automatically, there is normally no need to
configure them manually in /etc/fstab.
David Watson discovered that “umount -r” removed some restrictive
mount options like the “nosuid” flag. If /etc/fstab contains
user-mountable removable devices which specify the “nosuid” flag
(which is common practice for such devices), a local attacker could
exploit this to execute arbitrary programs with root privileges by
calling “umount -r” on a removable device.
This does not affect the default Ubuntu configuration. Since Ubuntu
mounts removable devices automatically, there is normally no need to
configure them manually in /etc/fstab.
Update instructions
In general, a standard system update will make all the necessary changes.
Learn more about how to get the fixes.The problem can be corrected by updating your system to the following package versions:
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