CVE-2018-11763

Apache2 mod_http2 header Denial of Service Vulnerability

Severity Score

5.9

*CVSS v3

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

In Apache HTTP Server 2.4.17 to 2.4.34, by sending continuous, large SETTINGS frames a client can occupy a connection, server thread and CPU time without any connection timeout coming to effect. This affects only HTTP/2 connections. A possible mitigation is to not enable the h2 protocol.

En Apache HTTP Server, de la versión 2.4.17 a la 2.4.34, mediante el envío continuo de tramas SETTINGS grandes, un cliente puede ocupar una conexión, hilo del servidor y tiempo de CPU sin que se active ningún agotamiento del tiempo de conexión. Esto solo afecta a las conexiones HTTP/2. Una posible mitigación es no activar el protocolo h2.

This vulnerability allows remote attackers to create a denial of service condition on vulnerable installations of Apache HTTPD server. Authentication is not required to exploit this vulnerability.
The specific flaw exists within the handling of HTTP2 headers. A crafted HTTP2 request can trigger a read past the end of an allocated buffer. An attacker can leverage this vulnerability to create a denial-of-service condition on the system.

*Credits: David Fiser

CVSS Scores

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

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

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

Low

Attack Vector

Network

Attack Complexity

Medium

Authentication

None

Confidentiality

None

Integrity

None

Availability

Partial

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2018-06-05 CVE Reserved
2018-09-25 CVE Published
2024-09-17 CVE Updated
2024-11-20 EPSS Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-20: Improper Input Validation

CAPEC

References (28)

URL	Tag	Source
http://www.securityfocus.com/bid/105414	Third Party Advisory
http://www.securitytracker.com/id/1041713	Third Party Advisory
https://lists.apache.org/thread.html/56c2e7cc9deb1c12a843d0dc251ea7fd3e7e80293cde02fcd65286ba%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/84a3714f0878781f6ed84473d1a503d2cc382277e100450209231830%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/r06f0d87ebb6d59ed8379633f36f72f5b1f79cadfda72ede0830b42cf%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/r15f9aa4427581a1aecb4063f1b4b983511ae1c9935e2a0a6876dad3c%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/r6521a7f62276340eabdb3339b2aa9a38c5f59d978497a1f794af53be%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/r76142b8c5119df2178be7c2dba88fde552eedeec37ea993dfce68d1d%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/r9f93cf6dde308d42a9c807784e8102600d0397f5f834890708bf6920%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/rc998b18880df98bafaade071346690c2bc1444adaa1a1ea464b93f0a%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/rd18c3c43602e66f9cdcf09f1de233804975b9572b0456cc582390b6f%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/re3d27b6250aa8548b8845d314bb8a350b3df326cacbbfdfe4d455234%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/rf6449464fd8b7437704c55f88361b66f12d5b5f90bcce66af4be4ba9%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/rfcf929bd33a6833e3f0c35eebdad70d5060665f9c4e17ea467c66770%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://security.netapp.com/advisory/ntap-20190204-0004	Third Party Advisory
https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbux03909en_us	Third Party Advisory
https://www.tenable.com/security/tns-2019-09	X_refsource_confirm

URL	Date	SRC

URL	Date	SRC
https://www.oracle.com/technetwork/security-advisory/cpuapr2019-5072813.html	2023-11-07
https://www.oracle.com/technetwork/security-advisory/cpujan2019-5072801.html	2023-11-07

URL	Date	SRC
http://lists.opensuse.org/opensuse-security-announce/2019-06/msg00030.html	2023-11-07
http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00056.html	2023-11-07
https://access.redhat.com/errata/RHSA-2018:3558	2023-11-07
https://access.redhat.com/errata/RHSA-2019:0366	2023-11-07
https://access.redhat.com/errata/RHSA-2019:0367	2023-11-07
https://httpd.apache.org/security/vulnerabilities_24.html	2023-11-07
https://usn.ubuntu.com/3783-1	2023-11-07
https://access.redhat.com/security/cve/CVE-2018-11763	2019-02-18
https://bugzilla.redhat.com/show_bug.cgi?id=1633399	2019-02-18

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				>= 2.4.17 <= 2.4.34 Search vendor "Apache" for product "Http Server" and version " >= 2.4.17 <= 2.4.34"		-		Affected
Canonical Search vendor "Canonical"		Ubuntu Linux Search vendor "Canonical" for product "Ubuntu Linux"				18.04 Search vendor "Canonical" for product "Ubuntu Linux" and version "18.04"		lts		Affected
Redhat Search vendor "Redhat"		Enterprise Linux Search vendor "Redhat" for product "Enterprise Linux"				6.0 Search vendor "Redhat" for product "Enterprise Linux" and version "6.0"		-		Affected
Redhat Search vendor "Redhat"		Enterprise Linux Search vendor "Redhat" for product "Enterprise Linux"				7.0 Search vendor "Redhat" for product "Enterprise Linux" and version "7.0"		-		Affected
Redhat Search vendor "Redhat"		Enterprise Linux Search vendor "Redhat" for product "Enterprise Linux"				7.4 Search vendor "Redhat" for product "Enterprise Linux" and version "7.4"		-		Affected
Redhat Search vendor "Redhat"		Enterprise Linux Search vendor "Redhat" for product "Enterprise Linux"				7.5 Search vendor "Redhat" for product "Enterprise Linux" and version "7.5"		-		Affected
Redhat Search vendor "Redhat"		Enterprise Linux Search vendor "Redhat" for product "Enterprise Linux"				7.6 Search vendor "Redhat" for product "Enterprise Linux" and version "7.6"		-		Affected
Oracle Search vendor "Oracle"		Enterprise Manager Ops Center Search vendor "Oracle" for product "Enterprise Manager Ops Center"				12.3.3 Search vendor "Oracle" for product "Enterprise Manager Ops Center" and version "12.3.3"		-		Affected
Oracle Search vendor "Oracle"		Hospitality Guest Access Search vendor "Oracle" for product "Hospitality Guest Access"				4.2.0 Search vendor "Oracle" for product "Hospitality Guest Access" and version "4.2.0"		-		Affected
Oracle Search vendor "Oracle"		Hospitality Guest Access Search vendor "Oracle" for product "Hospitality Guest Access"				4.2.1 Search vendor "Oracle" for product "Hospitality Guest Access" and version "4.2.1"		-		Affected
Oracle Search vendor "Oracle"		Instantis Enterprisetrack Search vendor "Oracle" for product "Instantis Enterprisetrack"				17.1 Search vendor "Oracle" for product "Instantis Enterprisetrack" and version "17.1"		-		Affected
Oracle Search vendor "Oracle"		Instantis Enterprisetrack Search vendor "Oracle" for product "Instantis Enterprisetrack"				17.2 Search vendor "Oracle" for product "Instantis Enterprisetrack" and version "17.2"		-		Affected
Oracle Search vendor "Oracle"		Instantis Enterprisetrack Search vendor "Oracle" for product "Instantis Enterprisetrack"				17.3 Search vendor "Oracle" for product "Instantis Enterprisetrack" and version "17.3"		-		Affected
Oracle Search vendor "Oracle"		Retail Xstore Point Of Service Search vendor "Oracle" for product "Retail Xstore Point Of Service"				7.0 Search vendor "Oracle" for product "Retail Xstore Point Of Service" and version "7.0"		-		Affected
Oracle Search vendor "Oracle"		Retail Xstore Point Of Service Search vendor "Oracle" for product "Retail Xstore Point Of Service"				7.1 Search vendor "Oracle" for product "Retail Xstore Point Of Service" and version "7.1"		-		Affected
Oracle Search vendor "Oracle"		Secure Global Desktop Search vendor "Oracle" for product "Secure Global Desktop"				5.4 Search vendor "Oracle" for product "Secure Global Desktop" and version "5.4"		-		Affected
Netapp Search vendor "Netapp"		Storage Automation Store Search vendor "Netapp" for product "Storage Automation Store"				-		-		Affected