CVE Vulnerabilities

CVE-2019-20201

Uncontrolled Resource Consumption

Published: Dec 31, 2019 | Modified: Jul 21, 2021
CVSS 3.x
6.5
MEDIUM
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
CVSS 2.x
4.3 MEDIUM
AV:N/AC:M/Au:N/C:N/I:N/A:P
RedHat/V2
RedHat/V3
Ubuntu
MEDIUM

An issue was discovered in ezXML 0.8.3 through 0.8.6. The ezxml_parse_* functions mishandle XML entities, leading to an infinite loop in which memory allocations occur.

Weakness

The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources.

Affected Software

Name Vendor Start Version End Version
Ezxml Ezxml_project 0.8.3 (including) 0.8.6 (including)
Mapcache Ubuntu bionic *
Mapcache Ubuntu groovy *
Mapcache Ubuntu hirsute *
Mapcache Ubuntu impish *
Mapcache Ubuntu kinetic *
Mapcache Ubuntu lunar *
Mapcache Ubuntu mantic *
Mapcache Ubuntu trusty *
Mapcache Ubuntu xenial *
Netcdf Ubuntu bionic *
Netcdf Ubuntu groovy *
Netcdf Ubuntu hirsute *
Netcdf Ubuntu impish *
Netcdf Ubuntu kinetic *
Netcdf Ubuntu lunar *
Netcdf Ubuntu mantic *
Netcdf Ubuntu trusty *
Netcdf Ubuntu trusty/esm *
Netcdf Ubuntu xenial *
Netcdf-parallel Ubuntu groovy *
Netcdf-parallel Ubuntu hirsute *
Netcdf-parallel Ubuntu impish *
Netcdf-parallel Ubuntu kinetic *
Netcdf-parallel Ubuntu lunar *
Netcdf-parallel Ubuntu mantic *
Netcdf-parallel Ubuntu trusty *
Netcdf-parallel Ubuntu xenial *
Scilab Ubuntu bionic *
Scilab Ubuntu groovy *
Scilab Ubuntu hirsute *
Scilab Ubuntu impish *
Scilab Ubuntu kinetic *
Scilab Ubuntu lunar *
Scilab Ubuntu mantic *
Scilab Ubuntu trusty *
Scilab Ubuntu xenial *

Extended Description

Limited resources include memory, file system storage, database connection pool entries, and CPU. If an attacker can trigger the allocation of these limited resources, but the number or size of the resources is not controlled, then the attacker could cause a denial of service that consumes all available resources. This would prevent valid users from accessing the product, and it could potentially have an impact on the surrounding environment. For example, a memory exhaustion attack against an application could slow down the application as well as its host operating system. There are at least three distinct scenarios which can commonly lead to resource exhaustion:

Resource exhaustion problems are often result due to an incorrect implementation of the following situations:

Potential Mitigations

  • Mitigation of resource exhaustion attacks requires that the target system either:

  • The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.

  • The second solution is simply difficult to effectively institute – and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.

References