RSI.0005.05-14-98.SUN.LIBNSL (w/ errata)

[bmartin () REPSEC COM (Brian Martin)]

        RSI would like to address some errata regarding the recent
        post and disclosure of one of our advisories.

        1. When mailed to members on 5-14-98, 'libnsl' was scheduled
           to be our third release. Delays in obtaining the patch
           forced it to be pushed back. As far as public releases,
           'libnsl' is #0005 (reference below)

        2. Sun is still working on a patch. The only 'patch' that has
           been supplied is a single libnsl replacement (in binary
           format) for a single version of Solaris (2.5.1). After
           further testing, it appears to have fixed the problems. RSI
           was waiting for an official patch for all versions before
           releasing this advisory.

        3. The (now) public release of #0005 (sun.libnsl) is below.
           Please reference this copy. The RSI web page (www.repsec.com)
           will be updated shortly to reflect the release.

        Thank you.

        Brian Martin
        RSI

-= official advisory =-


RSI.0005.05-14-98.SUN.LIBNSL



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                   Repent Security Incorporated, RSI
                       [ http://www.repsec.com ]


                       *** RSI ALERT ADVISORY ***


--- [CREDIT] --------------------------------------------------------------

Matt Conover: Discovered the vulnerabilities
Mark Zielinski: Author of advisory


--- [SUMMARY] -------------------------------------------------------------

Announced:     May 14, 1998
Report code:   RSI.0005.05-14-98.SUN.LIBNSL
Report title:  Sun Microsystem's libnsl
Vulnerability: Insufficient bounds checking
Vendor status: Contacted, patch under development
Patch status:  No patch available
Platforms:     Solaris 2.2, 2.3, 2.4, 2.5, 2.5.1
Vulnerable:    Several library functions in libnsl have buffer overflows
Reference:     http://www.repsec.com/advisories.html
Impact:        If exploited, an attacker could potentially compromise
               both local and remote root access on your server


--- [DETAILS] -------------------------------------------------------------

Problem:       Several buffer overflows exist in Sun Microsystem's libnsl
               networking library.

               While overwriting the buffer, the attacker can manipulate
               the stack and execute their own commands, possibly gaining
               root access on your server.

               Functions we have found vulnerable:

               Vulnerable key functions:
               ---------------------------------------------------

               extract_secret ()       : Buffer overflows while copying
                                         data into a local buffer
               getkeys_nis ()          : Buffer overflows if key value
                                         is larger then the buffer
               getpublickey ()         : Calls getkeys_nis ()
               getsecretkey ()         : Calls getkeys_nis ()


               Vulnerable RPC functions:
               ----------------------------------------------------

               authdes_seccreate ()    : Calls getpublickey ()
               rpc_broadcast_exp ()    : Buffer overflow if allowed to
                                         specify network protocol type
               rpc_broadcast ()        : Calls rpc_broadcast_exp ()
               clnt_create_timed ()    : Buffer overflow if allowed to
                                         specify network protocol type
               host2netname ()         : Buffer overflow while specifying
                                         hostname.
               getnetname ()           : Calls host2netname ()
               clnt_create ()          : Calls clnt_create_timed ()
               rpc_call ()             : Buffer overflow if allowed to
                                         specify network protocol type
               authdes_pk_seccreate () : Calls getnetname ()


               Vulnerable NIS functions:
               ----------------------------------------------------

               __nis_init_callback ()  : Calls getpublickey ()
               __nis_core_lookup ()    : Buffer overflow while copying
                                         paramaters into a local buffer
               nis_make_rpchandle ()   : Calls host2netname ()
               nis_dump_r ()           : Calls nis_make_rpchandle ()
               nis_dump ()             : Calls nis_dump_r ()
               __nis_auth2princ ()     : Buffer overflow while specifying
                                         machine name
               __nis_host2nis_server (): Buffer overflow while specifying
                                         hostname
               nis_name_of_r ()        : Buffer overflow while copying
                                         paramaters into a local buffer
               nis_old_data_r ()       : Buffer overflow while copying
                                         paramaters into a local buffer
               nis_list ()             : Calls __nis_core_lookup ()
               nis_add ()              : Calls nis_nameops ()
               nis_remove ()           : Calls nis_nameops ()
               nis_modify ()           : Calls nis_nameops ()
               nis_mkdir ()            : Calls nis_make_rpchandle ()
               nis_rmdir ()            : Calls nis_make_rpchandle ()


               Potentially vulnerable programs:
               ----------------------------------------------------

               Calls vulnerable RPC functions:

                 1. nfs mount
                 2. nfs share
                 3. rpc.rexd
                 4. autofs

               Calls vulnerable key functions:

                 1. chkey
                 2. keylogin
                 3. setkey
                 4. newkey
                 5. keyserv
                 6. libscheme

               Calls vulnerable NIS functions:

                 1. rpc.nisd
                 2. rpc.nisdpasswdd
                 3. nisping
                 4. nisaddent
                 5. nisupdkeys
                 6. nisaddcred
                 7. sendmail
                 8. volcheck
                 9. vold

               Calls vulnerable YP functions:

                 1. vacation
                 2. ypwhich
                 3. yppush


               These vulnerabilities are present in Sun Microsystem's
               Solaris 2.2, 2.3, 2.4, 2.5, and 2.5.1.

               For more information on this type of attack, point your
               web browsers to http://www.repsec.com/bofs.html.


--- [FIX] -----------------------------------------------------------------

Solution:      No fix available.


--- [PATCH] ---------------------------------------------------------------

Solution:      Sun Microsystem's has not released an official patch.


---------------------------------------------------------------------------

Repent Security Incorporated (RSI)
advise () repsec com
13610 N. Scottsdale Rd.
Suite #10-326
Scottsdale, AZ
85254

[ http://www.repsec.com ]

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