Vulnerabilities > CVE-2019-8961 - Uncontrolled Recursion vulnerability in Flexera Flexnet Publisher 11.16.2
Attack vector
NETWORK Attack complexity
LOW Privileges required
NONE Confidentiality impact
NONE Integrity impact
NONE Availability impact
HIGH Summary
A Denial of Service vulnerability related to stack exhaustion has been identified in FlexNet Publisher lmadmin.exe 11.16.2. Because the message reading function calls itself recursively given a certain condition in the received message, an unauthenticated remote attacker can repeatedly send messages of that type to cause a stack exhaustion condition.
Vulnerable Configurations
| Part | Description | Count |
|---|---|---|
| Application | 1 |
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- XML Nested Payloads Applications often need to transform data in and out of the XML format by using an XML parser. It may be possible for an attacker to inject data that may have an adverse effect on the XML parser when it is being processed. By nesting XML data and causing this data to be continuously self-referential, an attacker can cause the XML parser to consume more resources while processing, causing excessive memory consumption and CPU utilization. An attacker's goal is to leverage parser failure to his or her advantage. In most cases this type of an attack will result in a denial of service due to an application becoming unstable, freezing, or crash. However it may be possible to cause a crash resulting in arbitrary code execution, leading to a jump from the data plane to the control plane [R.230.1].
- XML Oversized Payloads Applications often need to transform data in and out of the XML format by using an XML parser. It may be possible for an attacker to inject data that may have an adverse effect on the XML parser when it is being processed. By supplying oversized payloads in input vectors that will be processed by the XML parser, an attacker can cause the XML parser to consume more resources while processing, causing excessive memory consumption and CPU utilization, and potentially cause execution of arbitrary code. An attacker's goal is to leverage parser failure to his or her advantage. In many cases this type of an attack will result in a denial of service due to an application becoming unstable, freezing, or crash. However it is possible to cause a crash resulting in arbitrary code execution, leading to a jump from the data plane to the control plane [R.231.1].
- 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.
- XML Parser Attack Applications often need to transform data in and out of the XML format by using an XML parser. It may be possible for an attacker to inject data that may have an adverse effect on the XML parser when it is being processed. These adverse effects may include the parser crashing, consuming too much of a resource, executing too slowly, executing code supplied by an attacker, allowing usage of unintended system functionality, etc. An attacker's goal is to leverage parser failure to his or her advantage. In some cases it may be possible to jump from the data plane to the control plane via bad data being passed to an XML parser. [R.99.1]
Nessus
| NASL family | Misc. |
| NASL id | FLEXNET_PUBLISHER_11_16_5_1_MULTI_VULNS.NASL |
| description | The Flexera FlexNet Publisher license server manager running on the remote host is affected by multiple vulnerabilities : - A denial of service (DoS) vulnerability exists in lmadmin due to improper handling of message fragments. An unauthenticated, remote attacker can exploit this issue, via a series of specially crafted messages, to cause the process to terminate. (CVE-2019-8960) - A denial of service (DoS) vulnerability exists in lmadmin due to stack exhaustion when receiving message fragments. An unauthenticated, remote attacker can exploit this issue, via a series of specially crafted messages, to cause the process to terminate. (CVE-2019-8961) |
| last seen | 2020-06-01 |
| modified | 2020-06-02 |
| plugin id | 133090 |
| published | 2020-01-20 |
| reporter | This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof. |
| source | https://www.tenable.com/plugins/nessus/133090 |
| title | Flexera FlexNet Publisher lmadmin < 11.16.5.1 Multiple Vulnerabilities |
| code | |
References
- https://community.flexera.com/t5/FlexNet-Publisher-Knowledge-Base/CVE-2019-8961-remediated-in-FlexNet-Publisher/ta-p/124601/jump-to/first-unread-message
- https://community.flexera.com/t5/FlexNet-Publisher-Knowledge-Base/CVE-2019-8961-remediated-in-FlexNet-Publisher/ta-p/124601/jump-to/first-unread-message