CVE request: temporary file issue in Passenger rubygem

["Vincent Danen" <vdanen () redhat com>]

Can a CVE be assigned to the following issue?

Phusion Passenger creates a "server instance directory" in /tmp during startup,
which is a temporary directory that Phusion Passenger uses to store working files.
This directory is deleted after Phusion Passenger exits. For various technical
reasons, this directory must have a semi-predictable filename. If a local attacker
can predict this filename, and precreates a symlink with the same filename that
points to an arbitrary directory with mode 755, owner root and group root, then
the attacker will succeed in making Phusion Passenger write files and create
subdirectories inside that target directory. The following files/subdirectories
are created:

* control_process.pid
* generation-X, where X is a number.

If you happen to have a file inside the target directory called `control_process.pid`,
then that file's contents are overwritten.

These files and directories are deleted during Phusion Passenger exit. The target
directory itself is not deleted, nor are any other contents inside the target
directory, although the symlink is.


It is fixed in upstream version 4.0.33.


References:

https://github.com/phusion/passenger/commit/34b1087870c2
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=736958
https://bugzilla.redhat.com/show_bug.cgi?id=1058992

-- 
Vincent Danen / Red Hat Security Response Team

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