glsa-200404-21.xml


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<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE glsa SYSTEM "http://www.gentoo.org/dtd/glsa.dtd">

<glsa id="200404-21">
  <title>Multiple Vulnerabilities in Samba</title>
  <synopsis>
    There is a bug in smbfs which may allow local users to gain root via a
    setuid file on a mounted Samba share. Also, there is a tmpfile symlink
    vulnerability in the smbprint script distributed with Samba.
  </synopsis>
  <product type="ebuild">samba</product>
  <announced>April 29, 2004</announced>
  <revised>April 29, 2004: 01</revised>
  <bug>41800</bug>
  <bug>45965</bug>
  <access>local </access>
  <affected>
    <package name="net-fs/samba" auto="yes" arch="*">
      <unaffected range="ge">3.0.2a-r2</unaffected>
      <vulnerable range="le">3.0.2a</vulnerable>
    </package>
  </affected>
  <background>
    <p>
    Samba is a package which allows UNIX systems to act as file servers for
    Windows computers. It also allows UNIX systems to mount shares exported by
    a Samba/CIFS/Windows server. smbmount is a program in the Samba package
    which allows normal users on a UNIX system to mount remote shares. smbprint
    is an example script included in the Samba package which can be used to
    facilitate network printing.
    </p>
  </background>
  <description>
    <p>
    Two vulnerabilities have been discovered in Samba. The first vulnerability
    allows a local user who has access to the smbmount command to gain root. An
    attacker could place a setuid-root binary on a Samba share/server he or she
    controls, and then use the smbmount command to mount the share on the
    target UNIX box. The remote Samba server must support UNIX extensions for
    this to work. This has been fixed in version 3.0.2a.
    </p>
    <p>
    The second vulnerability is in the smbprint script. By creating a symlink
    from /tmp/smbprint.log, an attacker could cause the smbprint script to
    write to an arbitrary file on the system. This has been fixed in version
    3.0.2a-r2.
    </p>
  </description>
  <impact type="normal">
    <p>
    Local users with access to the smbmount command may gain root access. Also,
    arbitrary files may be overwritten using the smbprint script.
    </p>
  </impact>
  <workaround>
    <p>
    To workaround the setuid bug, remove the setuid bits from the
    /usr/bin/smbmnt, /usr/bin/smbumount and /usr/bin/mount.cifs binaries.
    However, please note that this workaround will prevent ordinary users from
    mounting remote SMB and CIFS shares.
    </p>
    <p>
    To work around the smbprint vulnerability, set "debug=no" in the smbprint
    configuration.
    </p>
  </workaround>
  <resolution>
    <p>
    All users should update to the latest version of the Samba package.
    </p>
    <p>
    The following commands will perform the upgrade:
    </p>
    <code>
    # emerge sync

    # emerge -pv ">=net-fs/samba-3.0.2a-r2"
    # emerge ">=net-fs/samba-3.0.2a-r2"</code>
    <p>
    Those who are using Samba's password database also need to run the
    following command:
    </p>
    <code>
    # pdbedit --force-initialized-passwords</code>
    <p>
    Those using LDAP for Samba passwords also need to check the sambaPwdLastSet
    attribute on each account, and ensure it is not 0.
    </p>
  </resolution>
  <references>
    <uri link="http://www.securityfocus.com/archive/1/353222/2004-04-09/2004-04-15/1">BugTraq Thread: Samba 3.x + kernel 2.6.x local root vulnerability</uri>
    <uri link="http://seclists.org/lists/bugtraq/2004/Mar/0189.html">BugTraq: smbprint Vulnerability</uri>
  </references>
  <metadata tag="submitter">
    condordes
  </metadata>
</glsa>