// For flags

CVE-2018-20843

expat: large number of colons in input makes parser consume high amount of resources, leading to DoS

Severity Score

7.5
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

1
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

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).

En libexpat en Expat anterior a versión 2.2.7, una entrada XML incluyendo nombres XML que contienen una gran cantidad de "dos puntos", podría hacer que el analizador XML consuma una gran cantidad de recursos de RAM y CPU durante el procesamiento (lo suficiente como para ser utilizables en ataques de denegación de servicio) .

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.

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Attack Vector
Network
Attack Complexity
Low
Authentication
None
Confidentiality
None
Integrity
None
Availability
Complete
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2019-06-24 CVE Reserved
  • 2019-06-24 CVE Published
  • 2024-06-17 EPSS Updated
  • 2024-08-05 CVE Updated
  • 2024-08-05 First Exploit
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
CWE
  • CWE-400: Uncontrolled Resource Consumption
  • CWE-611: Improper Restriction of XML External Entity Reference
CAPEC
References (23)
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Libexpat Project
Search vendor "Libexpat Project"
Libexpat
Search vendor "Libexpat Project" for product "Libexpat"
< 2.2.7
Search vendor "Libexpat Project" for product "Libexpat" and version " < 2.2.7"
-
Affected
Canonical
Search vendor "Canonical"
Ubuntu Linux
Search vendor "Canonical" for product "Ubuntu Linux"
12.04
Search vendor "Canonical" for product "Ubuntu Linux" and version "12.04"
-
Affected
Canonical
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Ubuntu Linux
Search vendor "Canonical" for product "Ubuntu Linux"
14.04
Search vendor "Canonical" for product "Ubuntu Linux" and version "14.04"
esm
Affected
Canonical
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Ubuntu Linux
Search vendor "Canonical" for product "Ubuntu Linux"
16.04
Search vendor "Canonical" for product "Ubuntu Linux" and version "16.04"
lts
Affected
Canonical
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Ubuntu Linux
Search vendor "Canonical" for product "Ubuntu Linux"
18.04
Search vendor "Canonical" for product "Ubuntu Linux" and version "18.04"
lts
Affected
Canonical
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Ubuntu Linux
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18.10
Search vendor "Canonical" for product "Ubuntu Linux" and version "18.10"
-
Affected
Canonical
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Ubuntu Linux
Search vendor "Canonical" for product "Ubuntu Linux"
19.04
Search vendor "Canonical" for product "Ubuntu Linux" and version "19.04"
-
Affected
Debian
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Debian Linux
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8.0
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-
Affected
Debian
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Debian Linux
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9.0
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-
Affected
Fedoraproject
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Fedora
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29
Search vendor "Fedoraproject" for product "Fedora" and version "29"
-
Affected
Fedoraproject
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Fedora
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30
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-
Affected
Opensuse
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Leap
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15.0
Search vendor "Opensuse" for product "Leap" and version "15.0"
-
Affected
Opensuse
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Leap
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15.1
Search vendor "Opensuse" for product "Leap" and version "15.1"
-
Affected
Oracle
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Hospitality Res 3700
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>= 5.7 <= 5.7.6
Search vendor "Oracle" for product "Hospitality Res 3700" and version " >= 5.7 <= 5.7.6"
-
Affected
Oracle
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Http Server
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12.1.3.0
Search vendor "Oracle" for product "Http Server" and version "12.1.3.0"
-
Affected
Oracle
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Http Server
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12.2.1.4.0
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-
Affected
Oracle
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Outside In Technology
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8.5.4
Search vendor "Oracle" for product "Outside In Technology" and version "8.5.4"
-
Affected
Oracle
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Outside In Technology
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8.5.5
Search vendor "Oracle" for product "Outside In Technology" and version "8.5.5"
-
Affected
Tenable
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Nessus
Search vendor "Tenable" for product "Nessus"
< 8.15.0
Search vendor "Tenable" for product "Nessus" and version " < 8.15.0"
-
Affected