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