Yellow Dog Security Advisory: YDU-20030304-1

[yellowdog-updates@lists.terrasoftsolutions.com]

Yellow Dog Linux Security Announcement
--------------------------------------

Package:	sendmail
Issue Date:	March 04, 2003
Priority:	high
Advisory ID: 	YDU-20030304-1


1. 	Topic:

	Updated sendmail packages are available.


2. 	Problem:

	"During a code audit of Sendmail by ISS, a critical vulnerability was
	uncovered that affects unpatched versions of Sendmail prior to version
	8.12.8. A remote attacker can send a carefully crafted email message
	which, when processed by sendmail, causes arbitrary code to be
	executed as root.

	We are advised that a proof-of-concept exploit is known to exist, but
	is not believed to be in the wild.

	Since this is a message-based vulnerability, MTAs other than Sendmail
	may pass on the carefully crafted message. This means that unpatched
	versions of Sendmail inside a network could still be at risk even if
	they do not accept external connections directly.

	In addition, the restricted shell (SMRSH) in Sendmail allows attackers to
	bypass the intended restrictions of smrsh by inserting additional commands
	after "||" sequences or "/" characters, which are not properly filtered or
	verified. A sucessful attack would allow an attacker who has a local
	account on a system which has explicitly enabled smrsh to execute arbitrary
	binaries as themselves by utilizing their .forward file.

	All users are advised to update to these erratum packages."
	(from Red Hat Advisory)


3. 	Solution:

   	a) Updating via apt...
   	We suggest that you use the apt-get program to keep your
   	system up-to-date. The following command(s) will retrieve
   	and install the fixed version of this update onto your system:

		apt-get update
		apt-get install sendmail

   	b) Updating manually...
	Download the updates below and then run the following rpm command.
   	(Please use a mirror site)

		rpm -Fvh [filenames]
		ftp://ftp.yellowdoglinux.com/pub/yellowdog/updates/yellowdog-2.3/
			ppc/sendmail-8.11.6-23a.72.ppc.rpm
			ppc/sendmail-cf-8.11.6-23a.72.ppc.rpm
			ppc/sendmail-devel-8.11.6-23a.72.ppc.rpm
			ppc/sendmail-doc-8.11.6-23a.72.ppc.rpm


4. Verification

MD5 checksum			  Package
--------------------------------  ----------------------------
a204c252209d59600bfddb9eeb1b6f18  ppc/sendmail-8.11.6-23a.72.ppc.rpm
916517f67ecbb524aecf89d61ebd24f8  ppc/sendmail-cf-8.11.6-23a.72.ppc.rpm
28fdd43e4d952ebb54d6276654890e83  ppc/sendmail-devel-8.11.6-23a.72.ppc.rpm
2e531410ed6395ffafa1e597ed7bdec0  ppc/sendmail-doc-8.11.6-23a.72.ppc.rpm
6d5fa214631a0fd99da4fb51cfb08a0d  SRPMS/sendmail-8.11.6-23a.72.src.rpm

I wish to verify that each package has not been corrupted or tampered with,
examine the md5sum with the following command: rpm --checksig --nogpg filename


5. Misc.

Terra Soft has setup a moderated mailing list where these security, bugfix, and package
enhancement announcements will be posted. See http://lists.terrasoftsolutions.com/ for more
information.

For information regarding the usage of apt-get, see:
http://www.yellowdoglinux.com/support/solutions/ydl_general/apt-get.shtml