CVE-2016-8740

Apache 2.4.23 mod_http2 - Denial of Service

Severity Score

7.5

*CVSS v3

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

The mod_http2 module in the Apache HTTP Server 2.4.17 through 2.4.23, when the Protocols configuration includes h2 or h2c, does not restrict request-header length, which allows remote attackers to cause a denial of service (memory consumption) via crafted CONTINUATION frames in an HTTP/2 request.

El módulo mod_http2 en el Apache HTTP Server 2.4.17 hasta la versión 2.4.23, cuando la configuración Protocols incluye h2 o h2c, no restringe la longitud de la cabecera de petición, lo que permite a atacantes remotos provocar una denegación de servicio (corrupción de memoria) a través de marcos CONTINUATION manipulados en una petición HTTP/2.

A vulnerability was found in httpd's handling of the LimitRequestFields directive in mod_http2, affecting servers with HTTP/2 enabled. An attacker could send crafted requests with headers larger than the server's available memory, causing httpd to crash.

Red Hat JBoss Core Services is a set of supplementary software for Red Hat JBoss middleware products. This software, such as Apache HTTP Server, is common to multiple JBoss middleware products, and is packaged under Red Hat JBoss Core Services to allow for faster distribution of updates, and for a more consistent update experience. This release of Red Hat JBoss Core Services Apache HTTP Server 2.4.23 Service Pack 1 serves as a replacement for Red Hat JBoss Core Services Apache HTTP Server 2.4.23, and includes bug fixes, which are documented in the Release Notes document linked to in the References.

*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

High

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

Partial

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

2016-10-18 CVE Reserved
2016-12-05 CVE Published
2018-06-19 First Exploit
2024-08-06 CVE Updated
2025-03-30 EPSS Updated
---------- Exploited in Wild
---------- KEV Due Date

CWE

CWE-20: Improper Input Validation
CWE-399: Resource Management Errors
CWE-770: Allocation of Resources Without Limits or Throttling

CAPEC

References (32)

URL	Tag	Source
http://www.securityfocus.com/bid/94650	Third Party Advisory
http://www.securitytracker.com/id/1037388	Third Party Advisory
https://h20566.www2.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbux03725en_us	X_refsource_confirm
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/r04e89e873d54116a0635ef2f7061c15acc5ed27ef7500997beb65d6f%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/r476d175be0aaf4a17680ef98c5153b4d336eaef76fb2224cc94c463a%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/rb14daf9cc4e28d18cdc15d6a6ca74e565672fabf7ad89541071d008b%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/rcc44594d4d6579b90deccd4536b5d31f099ef563df39b094be286b9e%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/rd336919f655b7ff309385e34a143e41c503e133da80414485b3abcc9%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/re1e3a24664d35bcd0a0e793e0b5fc6ca6c107f99a1b2c545c5d4b467%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://security.netapp.com/advisory/ntap-20180423-0001	X_refsource_confirm
https://support.apple.com/HT208221	X_refsource_confirm
https://www.tenable.com/security/tns-2017-04	X_refsource_confirm

URL	Date	SRC
https://www.exploit-db.com/exploits/40909	2024-08-06
https://github.com/lcfpadilha/mac0352-ep4	2018-06-19
https://github.com/jptr218/apachedos	2021-08-20
http://packetstormsecurity.com/files/140023/Apache-HTTPD-Web-Server-2.4.23-Memory-Exhaustion.html	2024-08-06

URL	Date	SRC
https://github.com/apache/httpd/commit/29c63b786ae028d82405421585e91283c8fa0da3	2023-11-07

URL	Date	SRC
http://rhn.redhat.com/errata/RHSA-2017-1415.html	2023-11-07
https://access.redhat.com/errata/RHSA-2017:1161	2023-11-07
https://access.redhat.com/errata/RHSA-2017:1413	2023-11-07
https://access.redhat.com/errata/RHSA-2017:1414	2023-11-07
https://security.gentoo.org/glsa/201701-36	2023-11-07
https://access.redhat.com/security/cve/CVE-2016-8740	2017-06-07
https://bugzilla.redhat.com/show_bug.cgi?id=1401528	2017-06-07

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 Search vendor "Apache" for product "Http Server" and version "2.4.17"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.4.18 Search vendor "Apache" for product "Http Server" and version "2.4.18"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.4.19 Search vendor "Apache" for product "Http Server" and version "2.4.19"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.4.20 Search vendor "Apache" for product "Http Server" and version "2.4.20"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.4.21 Search vendor "Apache" for product "Http Server" and version "2.4.21"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.4.22 Search vendor "Apache" for product "Http Server" and version "2.4.22"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.4.23 Search vendor "Apache" for product "Http Server" and version "2.4.23"		-		Affected