MCI Telecommunications internetMCI Security Group Report Title: iMCI MIIGS Security Alert Report Name: Sun Microsystem's libns vulnerability Report Number: iMCISE:IMCIRSI:040598:01:P1R1 Report Date: 04/05/98 Report Format: Formal Report Classification: MCI Informational Report Reference: http://www.security.mci.net Report Distribution: iMCI Security, MCI Internal Internet Gateway Security (MIIGS), MCI Emergency Alert LiSt (MEALS) (names on file) -------------------------------------------------------------------------- RSI.0005.05-14-98.SUN.LIBNSL |:::. |::::: |::::. |::::: |::::: |::::. .. :: .. .. :: .. .. .. :: |:::: |:::: |:::: :::::: |::::: |:::: |: |: :: |: |: |:: |: |: :: |: :: |::::: |: |::::: |::::: |::::: 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 ] --------------------------------------------------------------------------- -----BEGIN PGP PUBLIC KEY BLOCK----- Version: 2.6.2 mQCNAzU6dqAAAAEEAOHt9a5vevjD8ZjsEmncEbFp2U7aeqvPTcF/8FJMilgOVp75 dshXvZixHsYU7flgCNzA7wLIQPWBQBrweLG6dx9gE9e5Ca6yAJxZg8wNsi06tZfP nvmvf6F/7xoWS5Ei4k3YKuzscxlyePNNKws6uUe2ZmwVoB+i3HHT44dOafMhAAUT tBpSZXBTZWMgPGFkdmlzZUByZXBzZWMuY29tPg== =ro8H -----END PGP PUBLIC KEY BLOCK----- Copyright May 1998 RepSec, Inc. 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