CVE-2018-20843
published 2019-06-24CVE-2018-20843: 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…
PriorityP343high7.5CVSS 3.1
AVNACLPRNUINSUCNINAH
EPSS
7.11%
93.5th percentile
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).
Affected
24 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| canonical | ubuntu_linux | — | — |
| canonical | ubuntu_linux | — | — |
| canonical | ubuntu_linux | — | — |
| canonical | ubuntu_linux | — | — |
| canonical | ubuntu_linux | — | — |
| canonical | ubuntu_linux | — | — |
| debian | debian_linux | — | — |
| debian | debian_linux | — | — |
| debian | expat | < expat 2.2.6-2 (bookworm) | expat 2.2.6-2 (bookworm) |
| debian | libxmltok | < expat 2.2.6-2 (bookworm) | expat 2.2.6-2 (bookworm) |
| fedoraproject | fedora | — | — |
| fedoraproject | fedora | — | — |
| libexpat_project | libexpat | < 2.2.7 | 2.2.7 |
| msrc | cbl_mariner_1.0_arm | — | — |
| msrc | cbl_mariner_1.0_x64 | — | — |
| msrc | cm1_expat_2.2.6-4_on_cbl_mariner_1.0 | — | — |
| opensuse | leap | — | — |
| opensuse | leap | — | — |
| oracle | hospitality_res_3700 | 5.7 – 5.7.6 | — |
| oracle | http_server | — | — |
| oracle | http_server | — | — |
| oracle | outside_in_technology | — | — |
| oracle | outside_in_technology | — | — |
| tenable | nessus | < 8.15.0 | 8.15.0 |
CVSS provenance
nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
nvdv2.07.8HIGHAV:N/AC:L/Au:N/C:N/I:N/A:C
osv7.5HIGH
vendor_debian7.5HIGH
vendor_msrc7.5HIGH
vendor_oracle7.5HIGH
vendor_redhat7.5HIGH
vendor_ubuntu6.8MEDIUM
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Ubuntu
xmltok library vulnerabilities
vendor_ubuntu·2025-01-13·CVSS 6.8
CVE-2019-15903 [MEDIUM] xmltok library vulnerabilities
Title: xmltok library vulnerabilities
Summary: Several security issues were fixed in libxmltok.
It was discovered that Expat, contained within the xmltok library,
incorrectly handled malformed XML data. If a user or application were
tricked into opening a crafted XML file, an attacker could cause a denial
of service, or possibly execute arbitrary code. (CVE-2015-1283,
CVE-2016-0718, CVE-2016-4472, CVE-2019-15903)
It was discovered that Expat, contained within the xmltok library,
incorrectly handled XML data containing a large number of colons, which
could lead to excessive resource consumption. If a user or application
were tricked into opening a crafted XML file, an attacker could possibly
use this issue to cause a denial of service. (CVE-2018-20843)
It was discovered that Expat, cont
CISA ICS
Siemens SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP V3.1
cisa_ics·2023-12-14
Siemens SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP V3.1
ICS Advisory
##
Siemens SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP V3.1
Release DateDecember 14, 2023
Alert CodeICSA-23-348-10
As of January 10, 2023, CISA will no longer be updating ICS security advisories for Siemens product vulnerabilities beyond the initial advisory. For the most up-to-date information on vulnerabilities in this advisory, please see Siemens' ProductCERT Security Advisories (CERT Services | Services | Siemens Global).
View CSAF
## 1. EXECUTIVE SUMMARY
- CVSS v3 9.8
- ATTENTION: Exploitable remotely/low attack complexity
- Vendor: Siemens
- Equipment: SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP V3.1
- Vulnerabilities: Improper Restriction of XML External Entity Reference, Time-of-check Time-of-use (TOCTOU) Race Condition, Command Injection, Miss
Ubuntu
xmltok library vulnerabilities
vendor_ubuntu·2022-07-19·CVSS 5.0
CVE-2021-46143 [MEDIUM] xmltok library vulnerabilities
Title: xmltok library vulnerabilities
Summary: Several security issues were fixed in libxmltok.
Tim Boddy, Gustavo Grieco and others discovered that Expat, that is
integrated in xmltok library, incorrectly handled certain files.
An attacker could possibly use these issues to cause a denial of
service, or possibly execute arbitrary code. These issues were only
addressed in Ubuntu 16.04 ESM. (CVE-2012-1148, CVE-2015-1283,
CVE-2016-0718, CVE-2016-4472, CVE-2018-20843, CVE-2019-15903,
CVE-2021-46143, CVE-2022-22822, CVE-2022-22823, CVE-2022-22824,
CVE-2022-22825, CVE-2022-22826, CVE-2022-22827)
It was discovered that Expat, that is integrated in xmltok library,
incorrectly handled encoding validation of certain files. An attacker
could possibly use this issue to cause a denial of service, o
Oracle
Oracle Oracle Fusion Middleware Risk Matrix: SSL Module (LibExpat) — CVE-2018-20843
vendor_oracle·2021-10-15·CVSS 7.5
CVE-2018-20843 [HIGH] Oracle Oracle Fusion Middleware Risk Matrix: SSL Module (LibExpat) — CVE-2018-20843
Oracle Oracle Fusion Middleware Risk Matrix: SSL Module (LibExpat) vulnerability
CVE: CVE-2018-20843
CVSS: 7.5
Protocol: HTTP
Remote exploit: Yes
Affected versions: Network
Advisory: cpuoct2021 (OCT 2021)
Oracle
Oracle Oracle Food and Beverage Applications Risk Matrix: Common (LibExpat) — CVE-2018-20843
vendor_oracle·2021-04-15·CVSS 7.5
CVE-2018-20843 [HIGH] Oracle Oracle Food and Beverage Applications Risk Matrix: Common (LibExpat) — CVE-2018-20843
Oracle Oracle Food and Beverage Applications Risk Matrix: Common (LibExpat) vulnerability
CVE: CVE-2018-20843
CVSS: 7.5
Protocol: HTTP
Remote exploit: Yes
Affected versions: Network
Advisory: cpuapr2021 (APR 2021)
Ubuntu
VTK vulnerabilities
vendor_ubuntu·2021-03-15
CVE-2018-20843 VTK vulnerabilities
Title: VTK vulnerabilities
Summary: Several security issues were fixed in VTK.
It was discovered that VTK incorrectly handled certain XML files in the
embedded Expat library. An attacker could possibly use this issue to cause
a denial of service or expose sensitive information.
Instructions: In general, a standard system update will make all the necessary changes.
Oracle
Oracle Oracle Fusion Middleware Risk Matrix: Installation (FreeType) — CVE-2018-20843
vendor_oracle·2020-04-15·CVSS 7.5
CVE-2018-20843 [HIGH] Oracle Oracle Fusion Middleware Risk Matrix: Installation (FreeType) — CVE-2018-20843
Oracle Oracle Fusion Middleware Risk Matrix: Installation (FreeType) vulnerability
CVE: CVE-2018-20843
CVSS: 7.5
Protocol: HTTP
Remote exploit: Yes
Affected versions: Network
Advisory: cpuapr2020 (APR 2020)
Ubuntu
Expat vulnerability
vendor_ubuntu·2019-06-26
CVE-2018-20843 Expat vulnerability
Title: Expat vulnerability
Summary: Expat could be made to consume a high amount of RAM and CPU resources
if it received a specially crafted XML file.
It was discovered that Expat incorrectly handled certain XML files.
An attacker could possibly use this issue to cause a denial of service.
Instructions: In general, a standard system update will make all the necessary changes.
Ubuntu
Expat vulnerability
vendor_ubuntu·2019-06-26
CVE-2018-20843 Expat vulnerability
Title: Expat vulnerability
Summary: Expat could be made to consume a high amount of RAM and CPU
resources if it received a specially crafted XML file.
USN-4040-1 fixed a vulnerability in expat. This update provides
the corresponding update for Ubuntu 12.04 ESM and Ubuntu 14.04 ESM.
Original advisory details:
It was discovered that Expat incorrectly handled certain XML files.
An attacker could possibly use this issue to cause a denial of service.
Instructions: In general, a standard system update will make all the necessary changes.
Red Hat
expat: large number of colons in input makes parser consume high amount of resources, leading to DoS
vendor_redhat·2019-06-24·CVSS 7.5
CVE-2018-20843 [HIGH] CWE-400 expat: large number of colons in input makes parser consume high amount of resources, leading to DoS
expat: large number of colons in input makes parser consume high amount of resources, leading to DoS
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).
It was discovered that the "setElementTypePrefix()" function incorrectly extracted XML namespace prefixes. By tricking an application into processing a specially crafted XML file, an attacker could cause unusually high consumption of memory resources and possibly lead to a denial of service.
Statement: When processing a specially crafted XML file, expat may use more memory than ultimately necessary, which can also lead to increased CPU usage and
Microsoft
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
vendor_msrc·2019-06-11·CVSS 7.5
CVE-2018-20843 [HIGH] CWE-611 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
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).
FAQ: Is Azure Linux the only Microsoft product that includes this open-source library and is therefore potentially affected by this vulnerability?
One of the main benefits to our customers who choose to use the Azure Linux distro is the commitment to keep it up to date with the most recent and most secure versions of the open source libraries with which the distro is composed. Microsoft is committed to transparency in this work which is why we began publishing CSAF/VEX in October 2025. See this blog post for more information. If impact to additiona
Debian
CVE-2018-20843: expat - In libexpat in Expat before 2.2.7, XML input including XML names that contain a ...
vendor_debian·2018·CVSS 7.5
CVE-2018-20843 [HIGH] CVE-2018-20843: expat - In libexpat in Expat before 2.2.7, XML input including XML names that contain a ...
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).
Scope: local
bookworm: resolved (fixed in 2.2.6-2)
bullseye: resolved (fixed in 2.2.6-2)
forky: resolved (fixed in 2.2.6-2)
sid: resolved (fixed in 2.2.6-2)
trixie: resolved (fixed in 2.2.6-2)
OSV
libxmltok vulnerabilities
osv·2025-01-13·CVSS 6.8
CVE-2015-1283 [MEDIUM] libxmltok vulnerabilities
libxmltok vulnerabilities
It was discovered that Expat, contained within the xmltok library,
incorrectly handled malformed XML data. If a user or application were
tricked into opening a crafted XML file, an attacker could cause a denial
of service, or possibly execute arbitrary code. (CVE-2015-1283,
CVE-2016-0718, CVE-2016-4472, CVE-2019-15903)
It was discovered that Expat, contained within the xmltok library,
incorrectly handled XML data containing a large number of colons, which
could lead to excessive resource consumption. If a user or application
were tricked into opening a crafted XML file, an attacker could possibly
use this issue to cause a denial of service. (CVE-2018-20843)
It was discovered that Expat, contained within the xmltok library,
incorrectly handled certain input, whi
OSV
libxmltok vulnerabilities
osv·2022-07-19·CVSS 5.0
CVE-2012-1148 [MEDIUM] libxmltok vulnerabilities
libxmltok vulnerabilities
Tim Boddy, Gustavo Grieco and others discovered that Expat, that is
integrated in xmltok library, incorrectly handled certain files.
An attacker could possibly use these issues to cause a denial of
service, or possibly execute arbitrary code. These issues were only
addressed in Ubuntu 16.04 ESM. (CVE-2012-1148, CVE-2015-1283,
CVE-2016-0718, CVE-2016-4472, CVE-2018-20843, CVE-2019-15903,
CVE-2021-46143, CVE-2022-22822, CVE-2022-22823, CVE-2022-22824,
CVE-2022-22825, CVE-2022-22826, CVE-2022-22827)
It was discovered that Expat, that is integrated in xmltok library,
incorrectly handled encoding validation of certain files. An attacker
could possibly use this issue to cause a denial of service, or
possibly execute arbitrary code. (CVE-2022-25235)
It was discovered
GHSA
GHSA-hj5j-c8qp-mgmv: In libexpat in Expat before 2
ghsa_unreviewed·2022-05-24
CVE-2018-20843 [HIGH] CWE-611 GHSA-hj5j-c8qp-mgmv: In libexpat in Expat before 2
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).
OSV
CVE-2018-20843: In libexpat in Expat before 2
osv·2019-06-24·CVSS 7.5
CVE-2018-20843 [HIGH] CVE-2018-20843: In libexpat in Expat before 2
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).
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2018-20843 mingw-expat: expat: large number of colons in input makes parser consume high amount of resources, leading to DoS [fedora-all]
bugzilla·2019-06-25·CVSS 7.5
CVE-2018-20843 [HIGH] CVE-2018-20843 mingw-expat: expat: large number of colons in input makes parser consume high amount of resources, leading to DoS [fedora-all]
CVE-2018-20843 mingw-expat: expat: large number of colons in input makes parser consume high amount of resources, leading to DoS [fedora-all]
This is an automatically created tracking bug! It was created to ensure
that one or more security vulnerabilities are fixed in affected versions
of fedora-all.
For comments that are specific to the vulnerability please use bugs filed
against the "Security Response" product referenced in the "Blocks" field.
For more information see:
http://fedoraproject.org/wiki/Security/TrackingBugs
When submitting as an update, use the fedpkg template provided in the next
comment(s). This will include the bug IDs of this tracking bug as well as
the relevant top-level CVE bugs.
Please also mention the CVE IDs being fixed in the RPM changelog and the
fedpkg commi
Bugzilla
CVE-2018-20843 expat: large number of colons in input makes parser consume high amount of resources, leading to DoS
bugzilla·2019-06-25·CVSS 7.5
CVE-2018-20843 [HIGH] CVE-2018-20843 expat: large number of colons in input makes parser consume high amount of resources, leading to DoS
CVE-2018-20843 expat: large number of colons in input makes parser consume high amount of resources, leading to DoS
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).
External References:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=931031
Upstream Issue:
https://github.com/libexpat/libexpat/issues/186
Discussion:
Created expat tracking bugs for this issue:
Affects: fedora-all [bug 1723724]
Created mingw-expat tracking bugs for this issue:
Affects: epel-7 [bug 1723726]
Affects: fedora-all [bug 1723725]
---
This vulnerability is out of security support scope for the following produ
Bugzilla
CVE-2018-20843 expat: large number of colons in input makes parser consume high amount of resources, leading to DoS [fedora-all]
bugzilla·2019-06-25·CVSS 7.5
CVE-2018-20843 [HIGH] CVE-2018-20843 expat: large number of colons in input makes parser consume high amount of resources, leading to DoS [fedora-all]
CVE-2018-20843 expat: large number of colons in input makes parser consume high amount of resources, leading to DoS [fedora-all]
This is an automatically created tracking bug! It was created to ensure
that one or more security vulnerabilities are fixed in affected versions
of fedora-all.
For comments that are specific to the vulnerability please use bugs filed
against the "Security Response" product referenced in the "Blocks" field.
For more information see:
http://fedoraproject.org/wiki/Security/TrackingBugs
When submitting as an update, use the fedpkg template provided in the next
comment(s). This will include the bug IDs of this tracking bug as well as
the relevant top-level CVE bugs.
Please also mention the CVE IDs being fixed in the RPM changelog and the
fedpkg commit message.
N
Bugzilla
CVE-2018-20843 mingw-expat: expat: large number of colons in input makes parser consume high amount of resources, leading to DoS [epel-7]
bugzilla·2019-06-25·CVSS 7.5
CVE-2018-20843 [HIGH] CVE-2018-20843 mingw-expat: expat: large number of colons in input makes parser consume high amount of resources, leading to DoS [epel-7]
CVE-2018-20843 mingw-expat: expat: large number of colons in input makes parser consume high amount of resources, leading to DoS [epel-7]
This is an automatically created tracking bug! It was created to ensure
that one or more security vulnerabilities are fixed in affected versions
of epel-7.
For comments that are specific to the vulnerability please use bugs filed
against the "Security Response" product referenced in the "Blocks" field.
For more information see:
http://fedoraproject.org/wiki/Security/TrackingBugs
When submitting as an update, use the fedpkg template provided in the next
comment(s). This will include the bug IDs of this tracking bug as well as
the relevant top-level CVE bugs.
Please also mention the CVE IDs being fixed in the RPM changelog and the
fedpkg commit messag
http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00039.htmlhttps://bugs.chromium.org/p/oss-fuzz/issues/detail?id=5226https://github.com/libexpat/libexpat/blob/R_2_2_7/expat/Changeshttps://github.com/libexpat/libexpat/issues/186https://github.com/libexpat/libexpat/pull/262https://github.com/libexpat/libexpat/pull/262/commits/11f8838bf99ea0a6f0b76f9760c43704d00c4ff6https://lists.debian.org/debian-lts-announce/2019/06/msg00028.htmlhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CEJJSQSG3KSUQY4FPVHZ7ZTT7FORMFVD/https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IDAUGEB3TUP6NEKJDBUBZX7N5OAUOOOK/https://seclists.org/bugtraq/2019/Jun/39https://security.gentoo.org/glsa/201911-08https://security.netapp.com/advisory/ntap-20190703-0001/https://support.f5.com/csp/article/K51011533https://usn.ubuntu.com/4040-1/https://usn.ubuntu.com/4040-2/https://www.debian.org/security/2019/dsa-4472https://www.oracle.com/security-alerts/cpuApr2021.htmlhttps://www.oracle.com/security-alerts/cpuapr2020.htmlhttps://www.oracle.com/security-alerts/cpuoct2020.htmlhttps://www.oracle.com/security-alerts/cpuoct2021.htmlhttps://www.tenable.com/security/tns-2021-11http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00039.htmlhttps://bugs.chromium.org/p/oss-fuzz/issues/detail?id=5226https://github.com/libexpat/libexpat/blob/R_2_2_7/expat/Changeshttps://github.com/libexpat/libexpat/issues/186https://github.com/libexpat/libexpat/pull/262https://github.com/libexpat/libexpat/pull/262/commits/11f8838bf99ea0a6f0b76f9760c43704d00c4ff6https://lists.debian.org/debian-lts-announce/2019/06/msg00028.htmlhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CEJJSQSG3KSUQY4FPVHZ7ZTT7FORMFVD/https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IDAUGEB3TUP6NEKJDBUBZX7N5OAUOOOK/https://seclists.org/bugtraq/2019/Jun/39https://security.gentoo.org/glsa/201911-08https://security.netapp.com/advisory/ntap-20190703-0001/https://support.f5.com/csp/article/K51011533https://usn.ubuntu.com/4040-1/https://usn.ubuntu.com/4040-2/https://www.debian.org/security/2019/dsa-4472https://www.oracle.com/security-alerts/cpuApr2021.htmlhttps://www.oracle.com/security-alerts/cpuapr2020.htmlhttps://www.oracle.com/security-alerts/cpuoct2020.htmlhttps://www.oracle.com/security-alerts/cpuoct2021.htmlhttps://www.tenable.com/security/tns-2021-11
2019-06-24
Published