Vulnerabilities
Misconfiguration
Compliance
CVE Vulnerabilities

CVE-2018-20843

Improper Restriction of XML External Entity Reference

Published: Jun 24, 2019 | Modified: May 30, 2025
CVSS 3.x
7.5
HIGH
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 2.x
7.8 HIGH
AV:N/AC:L/Au:N/C:N/I:N/A:C
RedHat/V2
RedHat/V3
7.5 MODERATE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Ubuntu
LOW
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Additional information
NVDhttps://nvd.nist.gov/vuln/detail/CVE-2018-20843
CWEhttps://cwe.mitre.org/data/definitions/611.html

In libexpat in Expat before 2.2.7, XML input including XML names that contain a large number of colons could make the XML parser consume a high amount of RAM and CPU resources while processing (enough to be usable for denial-of-service attacks).

Weakness

The product processes an XML document that can contain XML entities with URIs that resolve to documents outside of the intended sphere of control, causing the product to embed incorrect documents into its output.

Affected Software

NameVendorStart VersionEnd Version
LibexpatLibexpat_project*2.2.7 (excluding)
JBoss Core Services on RHEL 6RedHatjbcs-httpd24-curl-0:7.64.1-36.jbcs.el6*
JBoss Core Services on RHEL 6RedHatjbcs-httpd24-httpd-0:2.4.37-57.jbcs.el6*
JBoss Core Services on RHEL 6RedHatjbcs-httpd24-mod_cluster-native-0:1.3.14-4.Final_redhat_2.jbcs.el6*
JBoss Core Services on RHEL 6RedHatjbcs-httpd24-mod_http2-0:1.15.7-3.jbcs.el6*
JBoss Core Services on RHEL 6RedHatjbcs-httpd24-mod_jk-0:1.2.48-4.redhat_1.jbcs.el6*
JBoss Core Services on RHEL 6RedHatjbcs-httpd24-mod_md-1:2.0.8-24.jbcs.el6*
JBoss Core Services on RHEL 6RedHatjbcs-httpd24-mod_security-0:2.9.2-51.GA.jbcs.el6*
JBoss Core Services on RHEL 6RedHatjbcs-httpd24-nghttp2-0:1.39.2-25.jbcs.el6*
JBoss Core Services on RHEL 7RedHatjbcs-httpd24-curl-0:7.64.1-36.jbcs.el7*
JBoss Core Services on RHEL 7RedHatjbcs-httpd24-httpd-0:2.4.37-57.jbcs.el7*
JBoss Core Services on RHEL 7RedHatjbcs-httpd24-mod_cluster-native-0:1.3.14-4.Final_redhat_2.jbcs.el7*
JBoss Core Services on RHEL 7RedHatjbcs-httpd24-mod_http2-0:1.15.7-3.jbcs.el7*
JBoss Core Services on RHEL 7RedHatjbcs-httpd24-mod_jk-0:1.2.48-4.redhat_1.jbcs.el7*
JBoss Core Services on RHEL 7RedHatjbcs-httpd24-mod_md-1:2.0.8-24.jbcs.el7*
JBoss Core Services on RHEL 7RedHatjbcs-httpd24-mod_security-0:2.9.2-51.GA.jbcs.el7*
JBoss Core Services on RHEL 7RedHatjbcs-httpd24-nghttp2-0:1.39.2-25.jbcs.el7*
JBoss Core Services on RHEL 7RedHatjbcs-httpd24-openssl-pkcs11-0:0.4.10-7.jbcs.el7*
Red Hat Enterprise Linux 7RedHatexpat-0:2.1.0-12.el7*
Red Hat Enterprise Linux 8RedHatmingw-expat-0:2.2.4-5.el8*
Red Hat Enterprise Linux 8RedHatexpat-0:2.2.5-4.el8*
Red Hat Enterprise Linux 8.2 Advanced Update SupportRedHatexpat-0:2.2.10-1.el8_2*
Red Hat OpenShift DoRedHatopenshiftdo/odo-init-image-rhel7:1.1.3-2*
Text-Only JBCSRedHatexpat*
Apache2Ubuntutrusty*
Apr-utilUbuntutrusty*
AudacityUbuntukinetic*
AudacityUbuntulunar*
AudacityUbuntumantic*
AudacityUbuntutrusty*
AyttmUbuntutrusty*
AyttmUbuntuxenial*
CableswigUbuntutrusty*
CableswigUbuntuxenial*
CadaverUbuntubionic*
CadaverUbuntucosmic*
CadaverUbuntudisco*
CadaverUbuntueoan*
CadaverUbuntufocal*
CadaverUbuntugroovy*
CadaverUbuntuhirsute*
CadaverUbuntuimpish*
CadaverUbuntukinetic*
CadaverUbuntulunar*
CadaverUbuntumantic*
CadaverUbuntuoracular*
CadaverUbuntuplucky*
CadaverUbuntutrusty*
CadaverUbuntuxenial*
CmakeUbuntutrusty*
Coin3Ubuntubionic*
Coin3Ubuntucosmic*
Coin3Ubuntudisco*
Coin3Ubuntueoan*
Coin3Ubuntuesm-apps/bionic*
Coin3Ubuntuesm-apps/xenial*
Coin3Ubuntuesm-infra-legacy/trusty*
Coin3Ubuntugroovy*
Coin3Ubuntutrusty*
Coin3Ubuntutrusty/esm*
Coin3Ubuntuxenial*
ExpatUbuntubionic*
ExpatUbuntucosmic*
ExpatUbuntudevel*
ExpatUbuntudisco*
ExpatUbuntueoan*
ExpatUbuntuesm-infra-legacy/trusty*
ExpatUbuntuesm-infra/bionic*
ExpatUbuntuesm-infra/focal*
ExpatUbuntuesm-infra/xenial*
ExpatUbuntufocal*
ExpatUbuntugroovy*
ExpatUbuntuhirsute*
ExpatUbuntuimpish*
ExpatUbuntujammy*
ExpatUbuntukinetic*
ExpatUbuntulunar*
ExpatUbuntumantic*
ExpatUbuntunoble*
ExpatUbuntuoracular*
ExpatUbuntuplucky*
ExpatUbuntuquesting*
ExpatUbuntutrusty*
ExpatUbuntutrusty/esm*
ExpatUbuntuupstream*
ExpatUbuntuxenial*
FirefoxUbuntucosmic*
FirefoxUbuntudisco*
FirefoxUbuntutrusty*
GdcmUbuntutrusty*
GhostscriptUbuntutrusty*
InsighttoolkitUbuntutrusty*
InsighttoolkitUbuntuxenial*
Insighttoolkit4Ubuntuesm-apps/xenial*
Insighttoolkit4Ubuntutrusty*
Insighttoolkit4Ubuntuxenial*
LibxmltokUbuntubionic*
LibxmltokUbuntuesm-apps/bionic*
LibxmltokUbuntuesm-apps/focal*
LibxmltokUbuntuesm-apps/jammy*
LibxmltokUbuntuesm-apps/noble*
LibxmltokUbuntuesm-apps/xenial*
LibxmltokUbuntufocal*
LibxmltokUbuntuhirsute*
LibxmltokUbuntuimpish*
LibxmltokUbuntujammy*
LibxmltokUbuntukinetic*
LibxmltokUbuntulunar*
LibxmltokUbuntumantic*
LibxmltokUbuntunoble*
LibxmltokUbuntuoracular*
LibxmltokUbuntuplucky*
LibxmltokUbuntutrusty*
LibxmltokUbuntuupstream*
LibxmltokUbuntuxenial*
MatanzaUbuntubionic*
MatanzaUbuntucosmic*
MatanzaUbuntudevel*
MatanzaUbuntudisco*
MatanzaUbuntueoan*
MatanzaUbuntuesm-apps/bionic*
MatanzaUbuntuesm-apps/focal*
MatanzaUbuntuesm-apps/jammy*
MatanzaUbuntuesm-apps/noble*
MatanzaUbuntuesm-apps/xenial*
MatanzaUbuntufocal*
MatanzaUbuntugroovy*
MatanzaUbuntuhirsute*
MatanzaUbuntuimpish*
MatanzaUbuntujammy*
MatanzaUbuntukinetic*
MatanzaUbuntulunar*
MatanzaUbuntumantic*
MatanzaUbuntunoble*
MatanzaUbuntuoracular*
MatanzaUbuntuplucky*
MatanzaUbuntuquesting*
MatanzaUbuntutrusty*
MatanzaUbuntuxenial*
PocoUbuntutrusty*
SimgearUbuntutrusty*
SitecopyUbuntuoracular*
SitecopyUbuntuplucky*
SitecopyUbuntutrusty*
SmartUbuntutrusty*
Swish-eUbuntubionic*
Swish-eUbuntucosmic*
Swish-eUbuntudisco*
Swish-eUbuntueoan*
Swish-eUbuntufocal*
Swish-eUbuntugroovy*
Swish-eUbuntuhirsute*
Swish-eUbuntuimpish*
Swish-eUbuntukinetic*
Swish-eUbuntulunar*
Swish-eUbuntumantic*
Swish-eUbuntuoracular*
Swish-eUbuntuplucky*
Swish-eUbuntutrusty*
Swish-eUbuntuxenial*
TdomUbuntucosmic*
TdomUbuntutrusty*
Texlive-binUbuntutrusty*
ThunderbirdUbuntucosmic*
ThunderbirdUbuntudisco*
ThunderbirdUbuntutrusty*
Vnc4Ubuntubionic*
Vnc4Ubuntucosmic*
Vnc4Ubuntuesm-apps/bionic*
Vnc4Ubuntuesm-apps/xenial*
Vnc4Ubuntuesm-infra-legacy/trusty*
Vnc4Ubuntutrusty*
Vnc4Ubuntutrusty/esm*
Vnc4Ubuntuupstream*
Vnc4Ubuntuxenial*
VtkUbuntuesm-apps/xenial*
VtkUbuntuesm-infra-legacy/trusty*
VtkUbuntutrusty*
VtkUbuntutrusty/esm*
VtkUbuntuxenial*
Wbxml2Ubuntutrusty*
Wxwidgets2.8Ubuntutrusty*
Xmlrpc-cUbuntubionic*
Xmlrpc-cUbuntucosmic*
Xmlrpc-cUbuntudisco*
Xmlrpc-cUbuntueoan*
Xmlrpc-cUbuntufocal*
Xmlrpc-cUbuntugroovy*
Xmlrpc-cUbuntuhirsute*
Xmlrpc-cUbuntuimpish*
Xmlrpc-cUbuntukinetic*
Xmlrpc-cUbuntulunar*
Xmlrpc-cUbuntumantic*
Xmlrpc-cUbuntuoracular*
Xmlrpc-cUbuntuplucky*
Xmlrpc-cUbuntutrusty*
Xmlrpc-cUbuntutrusty/esm*
Xmlrpc-cUbuntuxenial*

Potential Mitigations

References

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