Vulnerabilities > CVE-2016-8374 - Resource Exhaustion vulnerability in Schneider-Electric products

047910
CVSS 7.8 - HIGH
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
NONE
Integrity impact
NONE
Availability impact
COMPLETE
network
low complexity
schneider-electric
CWE-400

Summary

An issue was discovered in Schneider Electric Magelis HMI Magelis GTO Advanced Optimum Panels, all versions, Magelis GTU Universal Panel, all versions, Magelis STO5xx and STU Small panels, all versions, Magelis XBT GH Advanced Hand-held Panels, all versions, Magelis XBT GK Advanced Touchscreen Panels with Keyboard, all versions, Magelis XBT GT Advanced Touchscreen Panels, all versions, and Magelis XBT GTW Advanced Open Touchscreen Panels (Windows XPe). An attacker may be able to disrupt a targeted web server, resulting in a denial of service because of UNCONTROLLED RESOURCE CONSUMPTION.

Common Attack Pattern Enumeration and Classification (CAPEC)

  • XML Ping of the Death
    An attacker initiates a resource depletion attack where a large number of small XML messages are delivered at a sufficiently rapid rate to cause a denial of service or crash of the target. Transactions such as repetitive SOAP transactions can deplete resources faster than a simple flooding attack because of the additional resources used by the SOAP protocol and the resources necessary to process SOAP messages. The transactions used are immaterial as long as they cause resource utilization on the target. In other words, this is a normal flooding attack augmented by using messages that will require extra processing on the target.
  • XML Entity Expansion
    An attacker submits an XML document to a target application where the XML document uses nested entity expansion to produce an excessively large output XML. XML allows the definition of macro-like structures that can be used to simplify the creation of complex structures. However, this capability can be abused to create excessive demands on a processor's CPU and memory. A small number of nested expansions can result in an exponential growth in demands on memory.
  • Inducing Account Lockout
    An attacker leverages the security functionality of the system aimed at thwarting potential attacks to launch a denial of service attack against a legitimate system user. Many systems, for instance, implement a password throttling mechanism that locks an account after a certain number of incorrect log in attempts. An attacker can leverage this throttling mechanism to lock a legitimate user out of their own account. The weakness that is being leveraged by an attacker is the very security feature that has been put in place to counteract attacks.
  • Violating Implicit Assumptions Regarding XML Content (aka XML Denial of Service (XDoS))
    XML Denial of Service (XDoS) can be applied to any technology that utilizes XML data. This is, of course, most distributed systems technology including Java, .Net, databases, and so on. XDoS is most closely associated with web services, SOAP, and Rest, because remote service requesters can post malicious XML payloads to the service provider designed to exhaust the service provider's memory, CPU, and/or disk space. The main weakness in XDoS is that the service provider generally must inspect, parse, and validate the XML messages to determine routing, workflow, security considerations, and so on. It is exactly these inspection, parsing, and validation routines that XDoS targets. There are three primary attack vectors that XDoS can navigate Target CPU through recursion: attacker creates a recursive payload and sends to service provider Target memory through jumbo payloads: service provider uses DOM to parse XML. DOM creates in memory representation of XML document, but when document is very large (for example, north of 1 Gb) service provider host may exhaust memory trying to build memory objects. XML Ping of death: attack service provider with numerous small files that clog the system. All of the above attacks exploit the loosely coupled nature of web services, where the service provider has little to no control over the service requester and any messages the service requester sends.

Seebug

bulletinFamilyexploit
description#### IMPROPER IMPLEMENTATION OF HTTP GET REQUEST ([CVE-2016-8367](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-8367) / SVE-82003201) The timeout value for closing an HTTP client's requests in the Web Gate service is too long and allows a malicious attacker to open multiple connections to the targeted web server and keep them open for as long as possible by continuously sending partial HTTP requests, none of which are ever completed. The attacked server opens more and more connections, waiting for each of the attack requests to be completed, which enables a single computer to take down the Web Gate Server. #### IMPROPER IMPLEMENTATION OF HTTP chunked Transfer-Encoding REQUEST ([CVE-2016-8374](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-8374) / SVE-82003202) The timeout value between chunks for closing an HTTP chunked encoding connection in the Web Gate service is too long and allows a malicious attacker to keep the connection open by exploiting the maximum possible interval between chunks and by using the Content-Length header and buffer the whole result set before calculating the total content size, which keeps the connection alive and enables a single computer to take down the Web Gate Server. ![](http://www.critifence.com/images/before_after.jpg)
idSSV:92511
last seen2017-11-19
modified2016-11-02
published2016-11-02
reporterRoot
titleSchneider Electric Magelis HMI Advanced Panel denial of service vulnerability (PanelShock)