Vulnerabilities > CVE-2012-6392 - Improper Input Validation vulnerability in Cisco Prime LAN Management Solution

047910
CVSS 10.0 - CRITICAL
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
COMPLETE
Integrity impact
COMPLETE
Availability impact
COMPLETE
network
low complexity
cisco
linux
CWE-20
critical
nessus

Summary

Cisco Prime LAN Management Solution (LMS) 4.1 through 4.2.2 on Linux does not properly validate authentication and authorization requests in TCP sessions, which allows remote attackers to execute arbitrary commands via a crafted session, aka Bug ID CSCuc79779.

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 familyGain a shell remotely
NASL idRSH_USERS.NASL
descriptionUsing common usernames as well as the usernames reported by
last seen2020-06-01
modified2020-06-02
plugin id10380
published2000-04-23
reporterThis script is Copyright (C) 2000-2018 Tenable Network Security, Inc.
sourcehttps://www.tenable.com/plugins/nessus/10380
titlersh Unauthenticated Access (via finger Information)
code
#
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
 script_id(10380);
 script_version("1.29");
 script_cvs_date("Date: 2018/07/27 18:38:14");

 script_cve_id("CVE-2012-6392");
 script_bugtraq_id(57221);
 script_xref(name:"CISCO-BUG-ID", value:"CSCuc79779");
 script_xref(name:"IAVA", value:"2013-A-0019");
 script_xref(name:"CISCO-SA", value:"cisco-sa-20130109-lms");

 script_name(english:"rsh Unauthenticated Access (via finger Information)");
 script_summary(english:"attempts to log in using rsh");

 script_set_attribute(attribute:"synopsis", value:"It was possible to log on this machine without password.");
 script_set_attribute(attribute:"description", value:
"Using common usernames as well as the usernames reported by 'finger',
Nessus was able to log in through rsh.  Either the accounts are not
protected by passwords or the ~/.rhosts files are not configured
properly. 

This vulnerability is confirmed to exist in Cisco Prime LAN Management
Solution, but could be present on any host that is not securely
configured.");
 script_set_attribute(attribute:"solution", value:
"If the remote host is a Cisco Prime LAN Management Solution virtual
appliance, apply the relevant patch referenced in Cisco security
advisory cisco-sa-20130109-lms. 

Otherwise, remove the .rhosts files or set a password on the impacted
accounts.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

 script_set_attribute(attribute:"plugin_publication_date", value:"2000/04/23");

 script_set_attribute(attribute:"plugin_type", value:"remote");
 script_set_attribute(attribute:"stig_severity", value:"I");
 script_set_attribute(attribute:"exploited_by_nessus", value:"true");
  script_end_attributes();

 script_category(ACT_ATTACK);

 script_copyright(english:"This script is Copyright (C) 2000-2018 Tenable Network Security, Inc.");
 script_family(english:"Gain a shell remotely");
 script_dependencie("find_service1.nasl", "finger.nasl", "rsh.nasl");
 script_require_ports("Services/rsh", 514);
 script_require_keys("rsh/active");
 script_exclude_keys("global_settings/supplied_logins_only");
 exit(0);
}

include("audit.inc");
include("global_settings.inc");

if (supplied_logins_only) audit(AUDIT_SUPPLIED_LOGINS_ONLY);

global_var tested, report;
tested = make_array();

report = '';

function login(rsh_port, name)
{
 local_var a, data, s1, s2, soc;

 if (tested[name]) return;
 tested[name] = 1;

 soc = open_priv_sock_tcp(dport:rsh_port);
 if (! soc) return;

  s1 = raw_string(0);
  s2 = name + raw_string(0) + name + raw_string(0) + "id" + raw_string(0);
  send(socket:soc, data:s1);
  send(socket:soc, data:s2);
  a = recv(socket:soc, length:1024);
  a += recv(socket:soc, length:1024);
  if("uid=" >< a )
  {
   a = str_replace(find:raw_string(0), replace:"", string:a);
   report = strcat(report,
"It was possible to log into this host using the account '", name , "'.
Here is the output of the 'id' command :
", a, '\n\n');
  }
  close(soc);
}

function test_finger(rsh_port, finger_port)
{
 local_var	finger, r, s;
 if (! get_port_state(finger_port)) return;
 finger = open_sock_tcp(finger_port);
 if (! finger) return;
 send(socket:finger, data: '\r\n');
 r = recv_line(socket:finger, length:1024);
 if (! r) { close(finger); return; }
 r = recv_line(socket:finger, length:1024);
 while(r)
 {
  s = strstr(r," ");
  r = r - s;
  login(name:r, rsh_port:rsh_port);
  r = recv_line(socket:finger, length:1024);
 }
 close(finger);
}

rsh_port = get_kb_item("Services/rsh");
if (! rsh_port) rsh_port = 514;
if (! get_port_state(rsh_port)) audit(AUDIT_PORT_CLOSED, rsh_port);

login(rsh_port:rsh_port, name:"root");

#
# these will most likely find backdoor rather
# than real unconfigured systems
#
login(rsh_port:rsh_port, name:"toor");
login(rsh_port:rsh_port, name:"bin");
login(rsh_port:rsh_port, name:"daemon");
login(rsh_port:rsh_port, name:"operator");
login(rsh_port:rsh_port, name:"nobody");
login(rsh_port:rsh_port, name:"adm");
login(rsh_port:rsh_port, name:"ftp");
login(rsh_port:rsh_port, name:"postgres");
login(rsh_port:rsh_port, name:"gdm");

finger_port = get_kb_item("Services/finger");
if(!finger_port)finger_port = 79;

test_finger(rsh_port: rsh_port, finger_port: finger_port);

if (report) security_hole(port: rsh_port, extra: report);