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		   Caldera International, Inc.  Security Advisory

Subject:		Linux: Name Service Cache Daemon (nscd) advisory
Advisory number: 	CSSA-2002-013.0
Issue date: 		2002, March 26
Cross reference:
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1. Problem Description

   The Name Service Cache Daemon  (nscd)  has a default behavior  that
   does not allow applications to  validate DNS "PTR" records  against
   "A" records.

   In particular, nscd caches a request for a "PTR" record, and when a
   request  comes later for the "A"  record,  nscd simply divulges the
   information from  the cached "PTR"  record, instead of querying the
   authoritative DNS for the "A" record.


2. Vulnerable Supported Versions

   System                       Package
   -----------------------------------------------------------
   OpenLinux Server 3.1          nscd
   
   OpenLinux Workstation 3.1     nscd
   
   OpenLinux Server 3.1.1        nscd
   
   OpenLinux Workstation  3.1.1  nscd


3. Solution

   Workaround

	Caldera  recommends that  this  problem  be  worked around  by
	disabling the hosts cache in the nscd configuration file:

	In /etc/nscd.conf, add the line

	enable-cache hosts no


4. References

   Specific references for this advisory:

	none


   Caldera OpenLinux security resources:

	http://www.caldera.com/support/security/index.html

   Caldera UNIX security resources:

	http://stage.caldera.com/support/security/


5. Disclaimer

   Caldera International, Inc. is  not  responsible for the misuse  of
   any  of the information we  provide on this  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.


6. Acknowledgements

   Louis Imershein (louisi@caldera.com) discovered and researched this
   vulnerability.
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