SAP DB web-tools multiple issues

["@stake Advisories" <advisories () atstake com>]

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                             @stake, Inc.
                           www.atstake.com

                          Security Advisory

Advisory Name: SAP DB web-tools multiple issues
Release Date: 11/17/2003
 Application: SAP DB < 7.4.03.30
    Platform: Linux (IA32)
              Microsoft Windows NT4/2000/XP
              SUN Solaris
              HPUX
              Compaq True64
    Severity: Remote file retrieval, administrative
              authentication bypass, authentication
              bypass,remote code execution
      Author: Ollie Whitehouse [ollie () atstake com]
Vendor Status: Vendor has patches
CVE Candidate: CAN-2003-0940 - web-tools directory traversal
              CAN-2003-0941 - Web Agent Administration available
              CAN-2003-0942 - overflow in Web Agent Administration
              CAN-2003-0943 - default services available in Web
                              Agent
              CAN-2003-0944 - buffer overflow in waecho
              CAN-2003-0945 - Web Database Manager predictable
                              session IDs
   Reference: www.atstake.com/research/advisories/2003/a111703-2.txt


Overview:

     SAP's (http://www.sapdb.org) open source database server
is a project which is sponsored by SAP AG. The database server
allows for a fast, flexible, high performance and easily administered
deployment of an enterprise level database solution. In addition
to the base package, the SAP DB project also ships a 'web-tools'
solution that can either be integrated in to existing web server
solutions (i.e. IIS or iPlanet) or alternatively run it's own native
web server.

There exists a number of vulnerabilities in the native web server
solution that @stake discovered which are outlined below that could
enable an  attacker to perform a number of operations that could be
used to mount an attack against the host in question and/or other
database servers which the web server can communicate with.

The vulnerabilities outlined below in the advisory are good examples
of why default functionality should be evaluated in terms of new
vulnerabilities and risks they may introduce before being deployed in
a production environment.


Details:

[1] Directory Traversal

Within the web-tools component their exists a directory traversal
vulnerability that enables and attacker to retrieve any file off
the host drive on which the web-tools component resides upon. Also
it should be noted that by default the SAP web servers runs as
Local SYSTEM by default on Windows NT/2000/XP Platforms so all files
are retrievable.

During a request no URL decoding occurs, simply put the request
is passed to the 'sqlopenc' function which checks the file requested
does indeed exist. If it is then the entire URI is simply supplied to
the 'FileFound' function which in turn returns the file to the user.
Contained below is the code, which is at fault:

    -----[Start: sqlfopenc Function]
    sqlfopenc (path, SP5VF_BINARY, SP5VF_READ, SP5BK_BUFFERED,
                  &fin, &err);
     if (err.sp5fe_result != vf_ok)
           rtc = FileNotFound(req->uri, host, port, as, rep);
     else
     {
          rtc = FileFound(path, as, req, rep, fin);
          sqlfclosec (fin, SP5VF_CLOSE_NORMAL, &err);
     }
     -----[End: sqlfopenc Function]

To successfully exploit this vulnerability an attacker simply needs
to perform a tried and tested double-dot attack to retrieve the file
of choice (i.e. 'http://127.0.0.1:85/../../../../../../boot.ini&apos;).


[2] Web Agent Administration open by default

By default any user who has access to the SAP DB web-tools can access
the Web Agent Administration pages without prior authentication by
simply requesting a URL similar to 'http://127.0.0.1:85/waadmin.wa&apos;.

- - From within the WAA an attacker can configure a large range of
options such as but not limited to:

    - Global Settings
    Configure such items as the SAP DB WWW document root.
   
    - Services
    Configure a URL which will call a certain function out of a
    library of choice (i.e. from DLL such as Kernel32 on Windows)

    - COM Services
    Configure a service than can call any class ID which is
    installed on the local machine.


[3] Web Agent Administration service contains buffer overflow

In addition the Web Agent Administration pages contain at least one
buffer overflow as well as the vulnerabilities mentioned above. By
entering a overly long URL such as:

  http://127.0.0.1:85/waadmin.wa?Service=Service&Name=AAAAAA....

An attacker can cause a buffer overflow to occur within, from
@stake's testing we were able to overwrite EIP (IA32) with EBX
pointing to our malicious buffer. If successfully exploited an
attacker can obtain 'SYSTEM' level access on Windows.


[4] Default services within Web Agent / WAECHO buffer overflow

Within the default installation of the SAP DB web-tools their
contains a number of default services. These services can be used
by an attacker to launch a mired of attacks against either the host
upon which they are installed or against other database servers with
which the SAP DB web-agent host has connectivity to.

    - waecho
    Within the SAP DB WWW (SAP Native, IIS or NES) there is a
    default service called waecho which is requested as via a URL
    similar to:

    http://127.0.0.1:85/waecho

    In response it simply spits out a number of variables the
    first of which is requestURI an example of which is contained
    below:

    requestURI = /waecho/

    By passing an overly long string on the URL such as:

    http://127.0.0.1:85/waecho/AAAAAAA....

    Will cause a buffer overflow to occur, EIP is over written
    (IA32) and EDI points to about 120 bytes before our buffer.
    If successfully exploited an attacker can execute code as
    'SYSTEM' on Windows platforms. The offending library
    (waecho.dll on Windows or vwd83echo.c within the source tree)
    contains the following offending code:

    -----[Start: wd83ShowVal function from vwd83echo.c]
    void wd83ShowVal( sapdbwa_HttpReplyP rep, const char *name,
                      const char *val )
    {
    char textBuffer[1024];
    if (val != NULL) {
         sprintf( textBuffer, name, val );
    } else {
         sprintf( textBuffer, name, "NULL" );
    }; /* else */
    strcat( textBuffer, "\n" );
    sapdbwa_SendBody( rep, textBuffer, strlen( textBuffer
                                 ) );
    } /* wd83ShowVal */
  
    -----[End: wd83ShowVal function from vwd83echo.c]

    - websql / webdbm
    Another two default services are the 'websql' and 'webdbm'
    functions rhese allow a remote user to either connect to and
    execute queries or manage a database if the database name,
    username and password are known. The issue here is that this
    can be utilized potentially by someone outside of the
    enterprise to connect to other databases which are not to be
    publicly accessible via web applications.

    Web SQL Interface: http://127.0.0.1:85/websql
    Web Database Manager: http://127.0.0.1:85/webdbm


[5] Web Database Manager session ID generation

Within the Web Database Manager there is the possibility of
performing a number of actions. To keep track of the session these an
ID is generated, but not kept in cookie as per the norm. Instead
these session ID's are stored in the URL. The manner in which these
session ID's are generated can be considered unsafe, below is sample
which @stake took:

    http://127.0.0.1:85/webdbm/014000000000
    http://127.0.0.1:85/webdbm/015000000000
    http://127.0.0.1:85/webdbm/016000000000
    http://127.0.0.1:85/webdbm/017000000000
    http://127.0.0.1:85/webdbm/018000000000
    http://127.0.0.1:85/webdbm/019000000000
    http://127.0.0.1:85/webdbm/020000000000

As you can see these session ID's simply increment by 1000000000 each
time.


Vendor Response:

    @stake have contacted the vendor multiple times since August
2002 until May 2003. below is the time line of the communication:


29-Aug-2002:    @stake confirms e-mail contact details of for
               security issues
29-Aug-2002:    @stake confirms SAP doesn't support encrypted
               e-mail
29-Aug-2002:    SAP confirms they have received it and passed
               it on to the developer who wrote the code.
03-Dec-2002:    @stake gets e-mail from SAP concerning another
               security issue they have resolved and a link
               to a URL.
Dec-2002:       @stake asks for status update from SAP.
Jan-2003:       @stake asks for status update from SAP.
24-Jan-2003:    Send e-mail to SAP asking if they received
               @stake's communications.
24-Jan-2003:    @stake gets confirmation e-mail back stating
               they are still trying to get a timeline
               together.
Mar-2003:       @stake asks for time line on when these issues
               will be fixed.
31-Mar-2003:    Get e-mail saying the priority for removing
               these flaws has been shifted down again.
18-Apr-2003:    @stake sends e-mail to SAP informing them of
               our advisory policy and it has been nearly 8
               months since initial communication on the
               vulnerabilities. @stake informs SAP of four
               (4) weeks notice until we release unless
               advised of an update schedule and that @stake is
               happy to delay release until a fix is available
               if they an supply a solid date/time frame
               by which the issues will be resolved.
21-Apr-2003:    Receive confirmation e-mail that my message
               has been passed on to the people developing
               the project plan. In addition @stake is
               informed they have been notified of all of
               @stake's past e-mails.
18-May-2003:    @stake e-mails contact saying no response has
               been heard.
??-May-2003:    Inform vendor we are releasing advisory and
               supply final @stake draft with time line in.
??-Jun-2003:    SAP reestablish contact
29-Aug-2003:    1 year since vendor notified
07-Nov-2003:    SAP releases version 7.4.03.30 which fixes all
               of the @stake reported vulnerabilities.
17-Nov-2003:    Release



Recommendation:

    If the SAP DB WWW service is not required then it should be removed
or disabled on the host in question. In addition to these as part of the
build procedures enterprises should look to remove all default services
if not required in production systems or adequately protect those that are
required.

In addition enterprises should look to deploy vendor patches for the above
vulnerabilities. Version 7.4.03.30 contains fixes for all vulnerabilities.


Common Vulnerabilities and Exposures (CVE) Information:

The Common Vulnerabilities and Exposures (CVE) project has assigned
the following names to these issues.  These are candidates for
inclusion in the CVE list (http://cve.mitre.org), which standardizes
names for security problems.

 CAN-2003-0940 - web-tools directory traversal
 CAN-2003-0941 - Web Agent Administration available
 CAN-2003-0942 - overflow in Web Agent Administration
 CAN-2003-0943 - default services available in Web Agent
 CAN-2003-0944 - buffer overflow in waecho
 CAN-2003-0945 - Web Database Manager predictable session IDs

@stake Vulnerability Reporting Policy:
http://www.atstake.com/research/policy/

@stake Advisory Archive:
http://www.atstake.com/research/advisories/

PGP Key:
http://www.atstake.com/research/pgp_key.asc

@stake is currently seeking application security experts to fill
several consulting positions.  Applicants should have strong
application development skills and be able to perform application
security design reviews, code reviews, and application penetration
testing.  Please send resumes to jobs () atstake com.

Copyright 2003 @stake, Inc. All rights reserved.

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