Bug 917904 (CVE-2013-1815)

Derek Higgins (derekh) of Red Hat reports:

packstack creates a answerfile containing configuration details for an 
openstack deployment. But after a recent comment in 
https://bugzilla.redhat.com/show_bug.cgi?id=906410 [Open URL] comment 4, I 
reviewed the code on how it is generated.

The file was being opened, written to and then the mode was being changed to 
600:

https://github.com/stackforge/packstack/blob/07a7897038bee143630fd84e95b3a4f5c89a5b47/packstack/installer/run_setup.py

def generateAnswerFile(outputFile, overrides={}):
    sep = os.linesep
    fmt = ("%(comment)s%(separator)s%(conf_name)s=%(default_value)s"
           "%(separator)s")
    outputFile = os.path.expanduser(outputFile)
    with open(outputFile, "w") as ans_file:
...
    os.chmod(outputFile, 0600)

and the answer path is provided by:

def _getanswerfilepath():
    path = None
    msg = "Could not find a suitable path on which to create the answerfile"

    # We'll use the first path with
    # write permissions. Order matters.
    for p in ["./", "~/", "/tmp"]:
        if os.access(p, os.W_OK):
            path = os.path.abspath(

The current directory "./" may be accessible to an attacker, and "/tmp" is 
definitely accessible to attackers. The file permissions should also be set
securely prior to placing the information in it.