CVE-2018-20843

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Summary

CVECVE-2018-20843
StatePUBLISHED
Assignermitre
Source PriorityCVE Program / NVD first with legacy fallback
Published2019-06-24 17:15:09 UTC
Updated2026-10-14 07:16:43 UTC
DescriptionIn 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).

Risk And Classification

Primary CVSS: v3.1 7.5 HIGH from [email protected]

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Problem Types: CWE-611 | n/a | CWE-611 CWE-611 Improper Restriction of XML External Entity Reference

VersionSourceTypeScoreSeverityVector
3.1[email protected]Primary7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
3.1ADPDECLARED7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
3.1134c704f-9b21-4f2e-91b3-4a467353bcc0Secondary7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
2.0[email protected]Primary7.8AV:N/AC:L/Au:N/C:N/I:N/A:C

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS v2.0 Breakdown

Access Vector
Network
Access Complexity
Low
Authentication
None
Confidentiality
None
Integrity
None
Availability
Complete

AV:N/AC:L/Au:N/C:N/I:N/A:C

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Operating System Canonical Ubuntu Linux 12.04 All All All
Operating System Canonical Ubuntu Linux 14.04 All All All
Operating System Canonical Ubuntu Linux 16.04 All All All
Operating System Canonical Ubuntu Linux 18.04 All All All
Operating System Canonical Ubuntu Linux 18.10 All All All
Operating System Canonical Ubuntu Linux 19.04 All All All
Operating System Debian Debian Linux 8.0 All All All
Operating System Debian Debian Linux 9.0 All All All
Operating System Fedoraproject Fedora 29 All All All
Operating System Fedoraproject Fedora 30 All All All
Application Libexpat Project Libexpat All All All All
Operating System Opensuse Leap 15.0 All All All
Operating System Opensuse Leap 15.1 All All All
Application Oracle Hospitality Res 3700 All All All All
Application Oracle Http Server 12.1.3.0 All All All
Application Oracle Http Server 12.2.1.4.0 All All All
Application Oracle Outside In Technology 8.5.4 All All All
Application Oracle Outside In Technology 8.5.5 All All All
Application Tenable Nessus All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Na N/a affected n/a Not specified
ADP Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP affected V3.1.0 V3.1.5 custom Not specified
ADP Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP affected V3.1.0 V3.1.5 custom Not specified
ADP Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP affected V3.1.0 V3.1.5 custom Not specified
ADP Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP affected V3.1.0 V3.1.5 custom Not specified
ADP Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP affected V3.1.0 V3.1.5 custom Not specified

References

ReferenceSourceLinkTags
cert-portal.siemens.com/productcert/html/ssa-398330.html 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e cert-portal.siemens.com
[CVE-2018-20843] 88k xml file uses >2G memory · Issue #186 · libexpat/libexpat · GitHub af854a3a-2127-422b-91ae-364da2661108 github.com Issue Tracking, Patch, Third Party Advisory
Oracle Critical Patch Update Advisory - October 2021 af854a3a-2127-422b-91ae-364da2661108 www.oracle.com Patch, Third Party Advisory
xmlparse.c: Fix extraction of namespace prefix from XML name (#186) by hartwork · Pull Request #262 · libexpat/libexpat · GitHub af854a3a-2127-422b-91ae-364da2661108 github.com Patch, Third Party Advisory
[SECURITY] [DLA 1839-1] expat security update af854a3a-2127-422b-91ae-364da2661108 lists.debian.org Mailing List, Third Party Advisory
[SECURITY] Fedora 30 Update: expat-2.2.7-1.fc30 - package-announce - Fedora Mailing-Lists af854a3a-2127-422b-91ae-364da2661108 lists.fedoraproject.org
Bugtraq: [SECURITY] [DSA 4472-1] expat security update af854a3a-2127-422b-91ae-364da2661108 seclists.org Mailing List, Third Party Advisory
USN-4040-1: Expat vulnerability | Ubuntu security notices | Ubuntu af854a3a-2127-422b-91ae-364da2661108 usn.ubuntu.com Third Party Advisory
CVE-2018-20843 Expat Vulnerability in NetApp Products | NetApp Product Security af854a3a-2127-422b-91ae-364da2661108 security.netapp.com Third Party Advisory
Oracle Critical Patch Update Advisory - April 2021 af854a3a-2127-422b-91ae-364da2661108 www.oracle.com Patch, Third Party Advisory
Expat: Multiple vulnerabilities (GLSA 201911-08) — Gentoo security af854a3a-2127-422b-91ae-364da2661108 security.gentoo.org Third Party Advisory
Oracle Critical Patch Update Advisory - October 2020 af854a3a-2127-422b-91ae-364da2661108 www.oracle.com Patch, Third Party Advisory
Oracle Critical Patch Update Advisory - April 2020 af854a3a-2127-422b-91ae-364da2661108 www.oracle.com Patch, Third Party Advisory
Debian -- Security Information -- DSA-4472-1 expat af854a3a-2127-422b-91ae-364da2661108 www.debian.org Third Party Advisory
xmlparse.c: Fix extraction of namespace prefix from XML name (#186) by hartwork · Pull Request #262 · libexpat/libexpat · GitHub af854a3a-2127-422b-91ae-364da2661108 github.com Exploit, Patch, Third Party Advisory
USN-4040-2: Expat vulnerability | Ubuntu security notices af854a3a-2127-422b-91ae-364da2661108 usn.ubuntu.com Third Party Advisory
5226 - oss-fuzz - OSS-Fuzz: Fuzzing the planet - Monorail af854a3a-2127-422b-91ae-364da2661108 bugs.chromium.org Issue Tracking, Third Party Advisory
[security-announce] openSUSE-SU-2019:1777-1: moderate: Security update f af854a3a-2127-422b-91ae-364da2661108 lists.opensuse.org Mailing List, Third Party Advisory
libexpat/Changes at R_2_2_7 · libexpat/libexpat · GitHub af854a3a-2127-422b-91ae-364da2661108 github.com Release Notes, Third Party Advisory
support.f5.com/csp/article/K51011533 af854a3a-2127-422b-91ae-364da2661108 support.f5.com Third Party Advisory
[SECURITY] Fedora 29 Update: expat-2.2.7-1.fc29 - package-announce - Fedora Mailing-Lists af854a3a-2127-422b-91ae-364da2661108 lists.fedoraproject.org
[R1] Nessus 8.15.0 Fixes Multiple Vulnerabilities - Security Advisory | Tenable® af854a3a-2127-422b-91ae-364da2661108 www.tenable.com Third Party Advisory
[SECURITY] Fedora 29 Update: expat-2.2.7-1.fc29 - package-announce - Fedora Mailing-Lists MITRE lists.fedoraproject.org
[SECURITY] Fedora 30 Update: expat-2.2.7-1.fc30 - package-announce - Fedora Mailing-Lists MITRE lists.fedoraproject.org
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Legacy QID Mappings

  • 375654 Tenable Nessus Multiple Vulnerabilities (TNS-2021-11)
  • 375688 F5 BIG-IP ASM,LTM,APM BIG-IP XML Parser Vulnerability (K51011533)
  • 375965 Oracle Hypertext Transfer Protocol Server (HTTP Server) Multiple Vulnerabilities (CPUOCT2021)
  • 376862 IBM Hypertext Transfer Protocol (HTTP) Server Multiple Vulnerabilities (964768)
  • 377390 Alibaba Cloud Linux Security Update for expat (ALINUX3-SA-2022:0042)
  • 377519 Alibaba Cloud Linux Security Update for expat (ALINUX2-SA-2020:0139)
  • 500180 Alpine Linux Security Update for expat
  • 503912 Alpine Linux Security Update for expat
  • 591406 Siemens SIMATIC S7-1500 CPU GNU/Linux subsystem Multiple Vulnerabilities (SSB-439005, ICSA-22-104-13)
  • 710115 Gentoo Linux Expat Multiple vulnerabilities (GLSA 201911-08)
  • 730076 IBM MQ Appliance Denial of Service Vulnerability (6403285)
  • 770068 Red Hat OpenShift Container Platform 4.6 Security Update (RHSA-2021:0436)
  • 900122 CBL-Mariner Linux Security Update for expat 2.2.6
  • 902970 Common Base Linux Mariner (CBL-Mariner) Security Update for expat (1830)
  • 940069 AlmaLinux Security Update for expat (ALSA-2020:4484)
  • 940279 AlmaLinux Security Update for mingw-expat (ALSA-2020:4846)
  • 960369 Rocky Linux Security Update for mingw-expat (RLSA-2020:4846)
  • 960835 Rocky Linux Security Update for expat (RLSA-2020:4484)

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