-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 NSFOCUS Security Advisory(SA2003-08) Topic: HP-UX libc NLSPATH Environment Variable Privilege Elevation Vulnerability Release Date: 2003-11-13 CVE CAN ID: CAN-2003-0090 http://www.nsfocus.com/english/homepage/research/0308.htm Affected system: =================== - - HP-UX B.11.00 - - HP-UX B.11.11 Summary: ========= NSFOCUS Security Team has found that the libc in HP-UX cannot restrict the NLSPATH variable used by suid root program, which causes a format string vulnerability. Exploiting the vulnerability local attacker could gain root privilege. Description: ============ Many programs in HP-UX use catopen()/catgets() and other functions in libc to display localized information. When catopen() has detected the environment variable NLSPATH, it will open the specified file and read messages from it. However, catopen() doesn't restrict the suid root program uses NLSPATH, which allows local attackers to set NLSPATH variable and specify a locale file crafted by themselves. When the suid root program uses catopen() to open the message file and passes the data from it to *printf(), it might cause a format string vulnerability. Any suid root program that uses catopen()/catgets() maybe vulnerable. By exploiting the vulnerability local attackers could gain root privilege. According to the test, at least the following programs are vulnerable: - -r-sr-xr-x 1 root bin 45056 Nov 14 2000 /usr/bin/at - -r-sr-xr-x 1 root bin 24576 Nov 14 2000 /usr/bin/crontab - -r-sr-xr-x 1 root bin 45056 Nov 14 2000 /usr/bin/ct - -r-sr-xr-x 1 root bin 36864 Apr 19 2001 /usr/bin/cu - -r-sr-xr-x 1 root bin 20480 Nov 14 2000 /usr/lbin/exrecover - -r-sr-xr-x 1 root bin 40960 Aug 16 2001 /usr/bin/lp - -r-sr-sr-x 2 root mail 45056 Nov 14 2000 /usr/bin/mail - -r-sr-xr-x 5 root bin 45056 Nov 14 2000 /usr/bin/passwd - -r-sr-xr-x 1 root bin 24576 Nov 14 2000 /usr/bin/su - -r-sr-xr-x 11 root bin 1921024 Nov 6 2001 /usr/sbin/swinstall - -r-sr-xr-x 2 root bin 1028096 Nov 6 2001 /usr/sbin/swpackage Workaround: ============= NSFOCUS suggests to temporarily remove the suid root bit for all the programs. However, it might brings about many inconvenience. You are suggested to apply the appropriate patch at the earliest possibility. Vendor Status: ============== 2002.11.19 Informed the vendor 2002.12.05 Vendor confirmed the vulnerability 2003.11.05 Vendor released a security bulletin (HPSBUX0311-294) and relative patches for the vulnerability. Detailed information for the HP security bulletin is available at: http://www1.itrc.hp.com/service/cki/docDisplay.do?docId=HPSBUX0311-294 Note: Valid ITRC account is required for the link above. Patch ID: HP-UX B.11.22 PHCO_29329 HP-UX B.11.11 PHCO_29495 HP-UX B.11.00 PHCO_29284 HP-UX B.10.20 PHCO_26158 Additional Information: ======================== The Common Vulnerabilities and Exposures (CVE) project has assigned the name CAN-2003-0090 to this issue. This is a candidate for inclusion in the CVE list (http://cve.mitre.org), which standardizes names for security problems. Candidates may change significantly before they become official CVE entries. Acknowledgment =============== Yang Jilong of NSFOCUS Security Team found the vulnerability. DISCLAIMS: ========== THE INFORMATION PROVIDED IS RELEASED BY NSFOCUS "AS IS" WITHOUT WARRANTY OF ANY KIND. NSFOCUS DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, EXCEPT FOR THE WARRANTIES OF MERCHANTABILITY. IN NO EVENT SHALL NSFOCUS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL,CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF NSFOCUS HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. DISTRIBUTION OR REPRODUCTION OF THE INFORMATION IS PROVIDED THAT THE ADVISORY IS NOT MODIFIED IN ANY WAY. Copyright 1999-2003 NSFOCUS. All Rights Reserved. Terms of use. NSFOCUS Security Team <security@private> NSFOCUS INFORMATION TECHNOLOGY CO.,LTD (http://www.nsfocus.com) PGP Key: http://www.nsfocus.com/homepage/research/pgpkey.asc Key fingerprint = F8F2 F5D1 EF74 E08C 02FE 1B90 D7BF 7877 C6A6 aF6DA -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.7 (GNU/Linux) iD8DBQE/s1KJ1794d8am9toRAjuxAJ9G7Y0zGPICg3Xi4HEOcWaTqAEXnwCfcMjj IrBO1cVWJ0MLfLUdK0C8fAY= =McFd -----END PGP SIGNATURE-----
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