Red Hat Bugzilla – Bug 78543
Mgetty 1.1.29 fixes security issue
Last modified: 2008-05-01 11:38:04 EDT
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Description of problem:
Mgetty 1.1.29 was just released, and fixes a security issue in
faxspool/faxrunqd. Here is the release announcement:
I have just released mgetty+sendfax 1.1.29.
It contains a couple of new features, bug fixes, and a massive rewrite of
the way the fax queue (/var/spool/fax/ and /var/spool/fax/outgoing/)
* many error messages clarified
* the caller's name (Caller ID) is now exported to external scripts
* voice/ has support for DLE shielding of long DTMF tones
* voice/ has support for 16 bit linear audio on V.253 modems
* lots of documentation work
Security fixes / concept changes:
* it's now possible to run faxrunq/faxrunqd (and thus sendfax) as
* fax spool directories are no longer world-writeable, access is done
via a suid helper program (suid to a special user ID, "fax")
* possible buffer overrun when calling cnd-program (if CallerName is
* $CALLER_ID, $CALLER_NAME and so on are sanitized before passing to shell
(all quote characters and all non-printable characters are replaced by "
* "caller name = CONNECTICUT" is now handled correctly, and not mistaken
for "CONNECT" any more
* faxrunqd sometimes didn't obey job priority settings if combining
multiple jobs to the same destination
* some timing problems in sending ATE0 to voice modems on fast computers
Who should upgrade?
* everbody who is using faxspool/faxrunq on a machine that is shared
with other users that are not 100 per cent trustworthy
* vgetty users with V.253 modems
- I strongly urge you to upgrade to 1.1.29 - older versions are NOT safe
if there are malicious users on the system and faxrunq/faxrunqd are in
- The fax queue handling (faxspool, faxq-helper) needs a new user ID
now ("fax") which MUST own the fax queue directories and SHOULD NOT
own anything else. The user ID is configured in the Makefile.
- faxrunq/faxrunqd can run as user "fax", but in that case the user
needs access to the modem devices (via his primary group id).
Watch out for log file access permissions if this is used!
If anything is unclear, *please* talk to me before rolling out updated
packages that might break things in funny ways.
USENET is *not* the non-clickable part of WWW!
Gert Doering - Munich, Germany
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. use faxspool/faxrunqd from mgetty < 1.1.29
Actual Results: FAX spool directories are world writable
Expected Results: Non world writable directories.
An errata has been issued which should help the problem described in this bug report.
This report is therefore being closed with a resolution of ERRATA. For more information
on the solution and/or where to find the updated files, please follow the link below. You may reopen
this bug report if the solution does not work for you.