___________________________________________________________________________ Caldera International, Inc. Security Advisory Subject: Open UNIX, UnixWare: OpenSSH channel code vulnerability Advisory number: CSSA-2002-SCO.11 Issue date: 2002 March 12 Cross reference: CSSA-2002-SCO.10 ___________________________________________________________________________ 0. Revision History 2002 March 20 This package requires the zlib and PRNGD libraries to install and run properly. Section 4.3 is updated below to include these packages. 1. Problem Description A bug exists in the channel code of OpenSSH versions 2.0 though 3.0.2. Existing users can use this bug to gain root privileges. The ability to exploit this vulnerability without an existing user account has not yet been proven, but it is considered possible. A malicious ssh server could also use this bug to exploit a connecting vulnerable client. 2. Vulnerable Supported Versions Operating System Version Affected Files ------------------------------------------------------------------ UnixWare 7.1.1 all ssh distribution files Open UNIX 8.0.0 all ssh distribution files 3. Workaround None. 4. Open UNIX, UnixWare 4.1 Location of Fixed Binaries ftp://stage.caldera.com/pub/security/openunix/CSSA-2002-SCO.11/ 4.2 Verification MD5 (openssh-3.1p1.pkg) = 795ce670574cfad348996be551cd498e md5 is available for download from ftp://stage.caldera.com/pub/security/tools/ 4.3 Installing Fixed Binaries Upgrade the affected binaries with the following commands: Download openssh-3.1p1.pkg to the /tmp directory # pkgadd -d /tmp/openssh-3.1p1.pkg NOTE: The zlib and PRNGD packages are required to be installed before OpenSSH will work. These packages can be downloaded from: ftp://ftp2.caldera.com/pub/skunkware/uw7/Packages/zlib-1.1.4.pkg ftp://ftp2.caldera.com/pub/skunkware/uw7/Packages/prngd-0.9.23.pkg They should be installed using the same procedure as the OpenSSH package. 5. References http://www.pine.nl/advisories/pine-cert-20020301.txt This and other advisories are located at http://stage.caldera.com/support/security This advisory addresses Caldera Security internal incidents sr861335, fz520314, erg711983. 6. Disclaimer Caldera International, Inc. is not responsible for the misuse of any of the information we provide on our website and/or through our security advisories. Our advisories are a service to our customers intended to promote secure installation and use of Caldera International products. 7. Acknowledgements Joost Pol discovered and researched this vulnerability. ___________________________________________________________________________