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Re: HP Web JetAdmin vulnerabilities.



Just a few more for HP Web JetAdmin 6.5 - I'm tired of waiting for HP and 
since the current version is way past 6.5, there is no point in hiding it 
any more :)

---[SNIP]---

Phenoelit Advisory <wir-haben-auch-mal-was-gefunden #0815 ++-+>

[ Title ]
        Multiple vulnerabilities in HP Web JetAdmin

[ Authors ]
        FX              <fx@xxxxxxxxxxxx>

        Phenoelit Group (http://www.phenoelit.de)
        Advisroy        
http://www.phenoelit.de/stuff/HP_Web_Jetadmin_advisory.txt

[ Affected Products ]
        Hewlett Packard (HP)  
                        Web JetAdmin 6.5 on any platform

        Partially affected:
                        Web JetAdmin 7.0 on any platform
                        Web JetAdmin <=6.2 on any platform

        HP Bug ID:      SSRT2397
        CERT VU ID:     VU#606673

[ Vendor communication ]
        10/28/02        Initial Notification, security-alert@xxxxxx
                        *Note-Initial notification by Phenoelit
                        includes a CC: to cert@xxxxxxxx by default

        From there on, communication went back and forth, while the major 
        version went up and only a subset of the bugs was fixed.

[ Overview ]
        HP Web JetAdmin is an enterprise management system for large amounts
        of HP printers, print servers and their respective print queues. The
        service provides a web interface for administration, by default
        listening on port 8000. The web server (HP-Web-Server-3.00.1696) is a
        modular service supporting plugins and using .hts and .inc files for
        creation of active content.

        From the readme_en.txt file:
         ''HP Web JetAdmin contains support for all HP JetDirect-connected
           printers and plotters. This product allows users to manage HP
           JetDirect-connected printers within their intranet using a
           browser. In addition to this, HP Web JetAdmin has the ability
           to discover and manage any non-HP printer that implements the
           standard printer MIB (RFC 1759). If a peripheral includes an
           embedded web server, HP Web JetAdmin provides a link to the
           home page of the peripheral.''
        
        NOTE: (Historic, see initial date!)
              Despite the fact that the HP web site still advertises it as
              6.5, the Web JetAdmin you can currently download is 7.0. This
              one features an Apache core and several improvements, including
              SSL support with a vulnerable version of OpenSSL (0.9.6c).
              Password decryption and direct calls of functions are still
              possible, but some of the exploited functions are no longer
              existing. 

[ Description ]
        Multiple vulnerabilities exist in the product. A short summary is
        outlined below:
        1  - Source disclosure of HTS and INC files
        2  - Real path disclosure of critical files
        3  - Critical files accessible through web server
        4  - User and Administrator password disclosure and decryption
        5  - User and Administrator password replay 
        6  - Root/Administrator password disclosure 
        7  - Denial of Service of the server due to input validation failure
        8  - Authentication circumvention on all functions
        9  - Direct access to methods of the server core and the plugins via
             the HTTP Protocol
        10 - Input validation failure for strings written to files
        11 - Root/Administrator compromise due to all of the above
        12 - Hidden games (easter egg) in the application

[ Vulnerability details ]
        [ 1 ]
        The web server will disclose the contents of the scripts, if a dot (.)
        is added to the end of the request URL.
        Example:
        http://server:8000/plugins/hpjwja/script/devices_list.hts.

        [ 2 ]
        Any page that is generated by the .HTS scripts will include a HTML
        comment line with the location of the file framework.ini, which holds
        several critical entries. 
        Example:
        <!-- framework.ini F:\Program Files\HP Web 
JetAdmin\doc\plugins\framework\framework.ini -->

        [ 3 ]
        The file framework.ini is located inside the web root directory. Any
        unauthenticated user can access it. This file contains the encrypted
        (see below) passwords for all users, permissions for the respective
        users and other valuable information.
        Example:
        http://server:8000/plugins/framework/framework.ini

        [ 4 ] 
        HP Web JetAdmin uses it's own encryption. Passwords will be encrypted
        on client side before send to the server using a Java applet. The
        encryption is easily broken and reversible. 
        An encrypted username or password is transmitted and stored in the
        ASCII representation of hexadecimal numbers. Such a ciphertext looks
        like 6a206d14000a7c2bc3cd3358153cffb5. This string has three elements:
        - 6a206d14 is the initialization vector for the algorithm
        - 000a is the length of the encrypted data (and double the length of 
          the clear text)
        - 7c2bc3cd3358153cffb5 is the actual encrypted data

        Encryption and decryption are performed by initializing a random
        number generator with the IV supplied in the string and performing an
        XOR operation with the encrypted data and the upper 8 bits of the 
        subsequently calculated random numbers. The following pseudo-code will
        be run:
        
        long v = IV;
        for(int i=0;i<strlen(code);i++){
                v = 31413L * v + 13849L & -1L;
                code[i]=code[i]^(char)(v >> 24);
        }

        As the result, the clear text will be in code[] as two-byte
        characters.
        
        [ 5 ]
        Because of the static nature of the encryption broken in point 4, an
        attacker can use password strings sniffed off the network and use them
        in selfmade HTTP requests to the service. This is commonly referred to
        as replay attack. 

        [ 6 ]
        When using services the host system provides only to administrative
        users (Administrator on Windows, root on UNIX), the web interface will
        require the user to enter the account data for this account. The
        entered username, password and (for Windows) the domain name are
        encrypted with the algorithm discussed in 4. Therefore, an attacker
        can sniff the strings off the network and decrypt the account
        information.

        [ 7 ]
        By modifying the "encrypted" string, an attacker can cause the service
        to lock up. As discussed in point 4, the second element in the string
        represents the length of the encrypted data. By replacing it with
        0xFFFF, the decryption function loops through the string until the
        index reaches -1, which never happend during tests and resulted in a
        completely frozen service.
        Example: 01010101FFFF02020202020202020202.

        [ 8 ]
        Access to the functionality of Web JetAdmin is usually done via HTTP
        POST requests. One of the variables always present is "obj". A typical
        request contains:
        
obj=Framework:CheckPassword;Httpd:SetProfile(Profiles_Admin,password,$_pwd,$__framework_ini)
        By leaving out the element "Framework:CheckPassword;", HP Web JetAdmin
        will no longer validate the supplied password and immediately grant
        access to the function specified. 
        Example: 
        obj=Httpd:SetProfile(Profiles_Admin,password,$_pwd,$__framework_ini)

        [ 9 ]
        The "obj" variable discussed in 8 is actually used to call functions
        in the server core or any plugin. The server core and the plugins
        export functions to be used via HTTP. Therefore, an attacker can craft
        HTTP POST requests to use internal functions. Additionally, use of
        variables and grouping of function calls are possible. One can
        actually write little programs and submit them to the server for
        execution. Most of the functions deal with internal data structures
        and files of HP Web JetAdmin.
        Example: see 8

        [ 10 ]
        HP Web JetAdmin uses a file called "cache.ini" outside of the web
        root. This file will contain session settings for a specific session.
        The session is identified by a variable called __BrowserID submitted
        in every HTTP request of the session. The format of cache.ini is:
        ---SNIP--
        [1234]
        Variable=Value
        NextVariable=NextValue

        [5678]
        ...
        ---SNIP--
        where 1234 and 5678 are the browser ID values. An attacker can
        influence the Variable=Value pairs through the call interface
        described in 9. By calling
        obj=Httpd:VarCacheSet(FX,MemberOfPhenoelit)&__BrowserID=0
        the following cache entry is created:
        [0]
        FX=MemberOfPhenoelit

        It is also possible to inject multiple lines at the beginning of the
        file by including HTTP encoded linefeed characters in the __BrowserID
        variable:
        &__BrowserID=%0aTest%20123%0a
        will create the following entry:
        [
        Test 123
        ]

        [ 11 ]
        The Httpd core supports an exported function called "ExecuteFile".
        This function takes two or more parameters. The first one is the path
        where the file is located (leave blank for use of $PATH or %PATH%) and
        the second is the executable itself. Combined with the ability to
        write arbitrary content to a file in a known location (see 10,
        location known due to 2), an attacker can easily start a program of
        his choice. Since the service usually runs as root on UNIX or as
        SYSTEM on Windows, this gives full remote access to the server. 
        Example: see Example section below

        [ 12 ]
        The security issues described above are not the result of a lack of
        time in the development department. This is proven by the fact that
        HP Web Jetadmin is delivered including two games.
        A text based adventure game is available on the URI:
        /plugins/hpjwja/script/special.hts?waycool=notyou
        The HTS file special2.hts features a hangman game and a list of
        developers. 
        Hint: When playing the text adventure, throw the cat toy around to
        keep the bad kitty busy.

[ Example ]

        The root/SYSTEM exploit for 6.5 (NOT 7.0) can be found at:
        http://www.phenoelit.de/hp/JetRoot_pl.txt

[ Solution ]
        None known at this time. HP Web JetAdmin 7.0 fixes some of the
        problems - namely removed the ExecuteFile function - but most of the
        issues and the games are still there.

[ end of file ]

-- 
         FX           <fx@xxxxxxxxxxxx>
      Phenoelit   (http://www.phenoelit.de)
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