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- **************************************************************************
- Security Bulletin 9313 DISA Defense Communications System
- July 2, 1993 Published by: DDN Security Coordination Center
- (SCC@NIC.DDN.MIL) 1-(800) 365-3642
-
- DEFENSE DATA NETWORK
- SECURITY BULLETIN
-
- The DDN SECURITY BULLETIN is distributed by the DDN SCC (Security
- Coordination Center) under DISA contract as a means of communicating
- information on network and host security exposures, fixes, and concerns
- to security and management personnel at DDN facilities. Back issues may
- be obtained via FTP (or Kermit) from NIC.DDN.MIL [192.112.36.5]
- using login="anonymous" and password="guest". The bulletin pathname is
- scc/ddn-security-yynn (where "yy" is the year the bulletin is issued
- and "nn" is a bulletin number, e.g. scc/ddn-security-9311).
- **************************************************************************
- -----------------------------------------------------------------------------
- CA-93:09a CERT Advisory
- July 1, 1993
- REVISION NOTICE: SunOS/Solaris /usr/lib/expreserve Vulnerability
- -----------------------------------------------------------------------------
-
-
- *** THIS IS A REVISED CERT ADVISORY ***
- *** IT CONTAINS SOLARIS PATCH INFORMATION ***
-
- The CERT Coordination Center has received updated patch information concerning
- a vulnerability in /usr/lib/expreserve in Sun Microsystems, Inc. (Sun)
- operating system (SunOS). This vulnerability affects all sun3 and sun4
- architectures and supported versions of SunOS including 4.1, 4.1.1, 4.1.2,
- 4.1.3, Solaris 2.0 (SunOS 5.0), Solaris 2.1 (SunOS 5.1), and Solaris 2.2
- (SunOS 5.2). This problem has become widely known, and CERT recommends that
- sites take action to address this vulnerability as soon as possible.
-
- Sun has produced a patch for SunOS 4.1, 4.1.1, 4.1.2, and 4.1.3 addressing
- this vulnerability for sun3 and sun4 architectures. Sun has also developed a
- patch for SunOS 5.x/Solaris 2.x systems. This revised advisory provides the
- information for obtaining the patch for SunOS 5.x/Solaris 2.x systems.
-
- A workaround is provided below that can be used on all systems, including
- Solaris, until a patch is installed.
-
- The patch can be obtained from local Sun Answer Centers worldwide as
- well as through anonymous FTP from the ftp.uu.net (192.48.96.9) system
- in the /systems/sun/sun-dist directory. In Europe, this patch is
- available from mcsun.eu.net (192.16.202.1) in the /sun/fixes directory.
-
- System Patch ID Filename BSD Checksum Solaris Checksum
- ------ -------- --------------- ----------- ----------------
- SunOS 101080-01 101080-01.tar.Z 45221 13 Not applicable
- Solaris 2.0 101119-01 101119-01.tar.Z 47944 27 61863 54
- Solaris 2.1 101089-01 101089-01.tar.Z 07227 27 4501 54
- Solaris 2.2 101090-01 101090-01.tar.Z 02491 27 44985 54
-
- The checksums shown above are from the BSD-based checksum (on Solaris,
- /usr/ucb/sum; on 4.x, /bin/sum) and from the SysV version that Sun released on
- Solaris (/usr/bin/sum). Please note that Sun sometimes updates patch files.
- If you find that the checksum is different please contact Sun or CERT for
- verification.
-
- -----------------------------------------------------------------------------
-
- I. Description
-
- Expreserve is a utility that preserves the state of a file being
- edited by vi(1) or ex(1) when an edit session terminates abnormally
- or when the system crashes. A vulnerability exists that allows
- users to overwrite any file on the system.
-
- II. Impact
-
- It is possible to gain root privileges using this vulnerability.
-
- III. Solution
-
- A. Obtain and install the appropriate patch according to the
- instructions included with the patch.
-
- B. Until you are able to install the appropriate patch, CERT
- recommends the following workaround be used on all systems.
- This workaround will disable expreserve functionality.
- The result of this workaround is that if vi(1) or ex(1) is running,
- and the sessions are interrupted, the files being edited will not
- be preserved and all edits not explicitly saved by the user will
- be lost. Users should be encouraged to save their files often.
-
- As root, remove the execute permissions on the existing
- /usr/lib/expreserve program:
-
- # /usr/bin/chmod a-x /usr/lib/expreserve
-
- ---------------------------------------------------------------------------
- The CERT Coordination Center wishes to thank Christopher Lott of
- Universitaet Kaiserslautern for reporting this vulnerability,
- and Sun Microsystems, Inc. for their response to this problem.
- ---------------------------------------------------------------------------
-
- If you believe that your system has been compromised, contact the CERT
- Coordination Center or your representative in FIRST (Forum of Incident
- Response and Security Teams).
-
- Internet E-mail: cert@cert.org
- Telephone: 412-268-7090 (24-hour hotline)
- CERT personnel answer 8:30 a.m.-5:00 p.m. EST(GMT-5)/EDT(GMT-4),
- and are on call for emergencies during other hours.
-
- CERT Coordination Center
- Software Engineering Institute
- Carnegie Mellon University
- Pittsburgh, PA 15213-3890
-
- Past advisories, information about FIRST representatives, and other
- information related to computer security are available for anonymous FTP
- from cert.org (192.88.209.5).
-
- ****************************************************************************
- * *
- * The point of contact for MILNET security-related incidents is the *
- * Security Coordination Center (SCC). *
- * *
- * E-mail address: SCC@NIC.DDN.MIL *
- * *
- * Telephone: 1-(800)-365-3642 *
- * *
- * NIC Help Desk personnel are available from 7:00 a.m.-7:00 p.m. EST, *
- * Monday through Friday except on federal holidays. *
- * *
- ****************************************************************************
-
-