Vulnerabilities > CVE-2017-14438 - Improper Input Validation vulnerability in Moxa Edr-810 Firmware 4.1

047910
CVSS 7.5 - HIGH
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
NONE
Integrity impact
NONE
Availability impact
HIGH
network
low complexity
moxa
CWE-20

Summary

Exploitable denial of service vulnerabilities exists in the Service Agent functionality of Moxa EDR-810 V4.1 build 17030317. A specially crafted packet can cause a denial of service. An attacker can send a large packet to 4000/tcp to trigger this vulnerability.

Vulnerable Configurations

Part Description Count
OS
Moxa
1
Hardware
Moxa
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.

Seebug

bulletinFamilyexploit
description### Summary Exploitable denial of service vulnerabilities exists in the Service Agent functionality of Moxa EDR-810 V4.1 build 17030317. A specially crafted packet can cause a denial of service. An attacker can send a large packet to 4000/tcp and 4001/tcp to trigger this vulnerability. ### Tested Versions Moxa EDR-810 V4.1 build 17030317 ### Product URLs https://www.moxa.com/product/EDR-810.htm ### CVSSv3 Score 7.5 - CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H ### CWE CWE-20 - Improper Input Validation ### Details The Moxa EDR Service Agent listens on port 4000 (tcp/udp) and 4001 (tcp). Moxa MXconfig, a Windows program, interacts with the EDR via the ServiceAgent. Sending large amounts of random data to these ports causes a crash. ### CVE-2017-14438 - Crash on Port 4000 In order to crash port 4000 (both TCP & UDP) a large packet needs to be sent to tcp/4000. This causes a consistent crash. ### Port 4001 In order to crash port 4001 a large packet needs to be sent to tcp/4001. The crash does not always occur on the first try so an attacker may need to run this attack multiple times in order to cause a crash. ### Exploit Proof-of-Concept This python script will crash the Service Agent ``` import socket host = '192.168.127.254' port = 4000 packet = "\x00" * 5000 s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.connect((host, port)) s.send(packet) data = s.recv(1024) s.close ``` ### Timeline * 2017-11-30 - Vendor Disclosure * 2017-12-04 - Vendor Acknowledged * 2017-12-25 - Vendor provided timeline for fix (Feb 2018) * 2018-01-04 - Timeline pushed to mid-March per vendor * 2018-03-24 - Talos follow up with vendor for release timeline * 2018-03-26 - Timeline pushed to 4/13/18 per vendor * 2018-04-12 - Vendor patched & published new firmware on website * 2018-04-13 - Public Release
idSSV:97229
last seen2018-06-26
modified2018-04-16
published2018-04-16
reporterMy Seebug
sourcehttps://www.seebug.org/vuldb/ssvid-97229
titleMoxa EDR-810 Service Agent Multiple Denial of Service Vulnerabilities(CVE-2017-14438 - CVE-2017-14439)

Talos

idTALOS-2017-0487
last seen2019-05-29
published2018-04-13
reporterTalos Intelligence
sourcehttp://www.talosintelligence.com/vulnerability_reports/TALOS-2017-0487
titleMoxa EDR-810 Service Agent Multiple Denial of Service Vulnerabilities