CVE-2020-11993

httpd: mod_http2 concurrent pool usage

Severity Score

7.5

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

Apache HTTP Server versions 2.4.20 to 2.4.43 When trace/debug was enabled for the HTTP/2 module and on certain traffic edge patterns, logging statements were made on the wrong connection, causing concurrent use of memory pools. Configuring the LogLevel of mod_http2 above "info" will mitigate this vulnerability for unpatched servers.

Apache HTTP Server versiones 2.4.20 hasta 2.4.43, cuando trace/debug fue habilitado para el módulo HTTP/2 y en determinados patrones de tráfico de borde, se hicieron declaraciones de registro en la conexión errónea, causando un uso concurrente de grupos de memoria. Configurando el LogLevel de mod_http2 sobre "info" mitigará esta vulnerabilidad para los servidores sin parches

A flaw was found in Apache httpd in versions 2.4.20 to 2.4.43. Logging using the wrong pool by mod_http2 at debug/trace log level may lead to potential crashes and denial of service. The highest threat from this vulnerability is to system availability.

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 adds the new Apache HTTP Server 2.4.37 Service Pack 5 packages that are part of the JBoss Core Services offering. This release serves as a replacement for Red Hat JBoss Core Services Pack Apache Server 2.4.37 Service Pack 4 and includes bug fixes and enhancements. Issues addressed include buffer overflow and integer overflow vulnerabilities.

*Credits: N/A

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

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

2020-04-21 CVE Reserved
2020-08-07 CVE Published
2024-08-04 CVE Updated
2024-08-04 First Exploit
2025-03-30 EPSS Updated
---------- Exploited in Wild
---------- KEV Due Date

CWE

CWE-400: Uncontrolled Resource Consumption
CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

CAPEC

References (28)

URL	Tag	Source
https://lists.apache.org/thread.html/r06f0d87ebb6d59ed8379633f36f72f5b1f79cadfda72ede0830b42cf%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/r09bb998baee74a2c316446bd1a41ae7f8d7049d09d9ff991471e8775%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/r2c6083f6a2027914a0f5b54e2a1f4fa98c03f8693b58460911818255%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/r3c5c3104813c1c5508b55564b66546933079250a46ce50eee90b2e36%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/r5debe8f82728a00a4a68bc904dd6c35423bdfc8d601cfb4579f38bf1%40%3Cdev.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/r623de9b2b2433a87f3f3a15900419fc9c00c77b26936dfea4060f672%40%3Cdev.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/r9e9f1a7609760f0f80562eaaec2aa3c32d525c3e0fca98b475240c71%40%3Cdev.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/rdf3e5d0a5f5c3d90d6013bccc6c4d5af59cf1f8c8dea5d9a283d13ce%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/rf71eb428714374a6f9ad68952e23611ec7807b029fd6a1b4f5f732d9%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://security.netapp.com/advisory/ntap-20200814-0005	Third Party Advisory
https://www.oracle.com/security-alerts/cpujan2021.html	Third Party Advisory

URL	Date	SRC
http://packetstormsecurity.com/files/160393/Apache-2-HTTP2-Module-Concurrent-Pool-Usage.html	2024-08-04

URL	Date	SRC

URL	Date	SRC
http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00068.html	2023-11-07
http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00071.html	2023-11-07
http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00081.html	2023-11-07
https://httpd.apache.org/security/vulnerabilities_24.html#CVE-2020-11993	2023-11-07
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4NKWG2EXAQQB6LMLATKZ7KLSRGCSHVAN	2023-11-07
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ITVFDBVM6E3JF3O7RYLRPRCH3RDRHJJY	2023-11-07
https://security.gentoo.org/glsa/202008-04	2023-11-07
https://usn.ubuntu.com/4458-1	2023-11-07
https://www.debian.org/security/2020/dsa-4757	2023-11-07
https://www.oracle.com/security-alerts/cpuoct2020.html	2023-11-07
https://access.redhat.com/security/cve/CVE-2020-11993	2021-05-18
https://bugzilla.redhat.com/show_bug.cgi?id=1866564	2021-05-18

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"				>= 2.4.20 <= 2.4.43 Search vendor "Apache" for product "Http Server" and version " >= 2.4.20 <= 2.4.43"		-		Affected
Netapp Search vendor "Netapp"		Clustered Data Ontap Search vendor "Netapp" for product "Clustered Data Ontap"				-		-		Affected
Canonical Search vendor "Canonical"		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 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
Canonical Search vendor "Canonical"		Ubuntu Linux Search vendor "Canonical" for product "Ubuntu Linux"				20.04 Search vendor "Canonical" for product "Ubuntu Linux" and version "20.04"		lts		Affected
Opensuse Search vendor "Opensuse"		Leap Search vendor "Opensuse" for product "Leap"				15.1 Search vendor "Opensuse" for product "Leap" and version "15.1"		-		Affected
Opensuse Search vendor "Opensuse"		Leap Search vendor "Opensuse" for product "Leap"				15.2 Search vendor "Opensuse" for product "Leap" and version "15.2"		-		Affected
Debian Search vendor "Debian"		Debian Linux Search vendor "Debian" for product "Debian Linux"				10.0 Search vendor "Debian" for product "Debian Linux" and version "10.0"		-		Affected
Fedoraproject Search vendor "Fedoraproject"		Fedora Search vendor "Fedoraproject" for product "Fedora"				31 Search vendor "Fedoraproject" for product "Fedora" and version "31"		-		Affected
Fedoraproject Search vendor "Fedoraproject"		Fedora Search vendor "Fedoraproject" for product "Fedora"				32 Search vendor "Fedoraproject" for product "Fedora" and version "32"		-		Affected
Oracle Search vendor "Oracle"		Communications Element Manager Search vendor "Oracle" for product "Communications Element Manager"				>= 8.2.0 <= 8.2.2 Search vendor "Oracle" for product "Communications Element Manager" and version " >= 8.2.0 <= 8.2.2"		-		Affected
Oracle Search vendor "Oracle"		Communications Session Report Manager Search vendor "Oracle" for product "Communications Session Report Manager"				>= 8.2.0 <= 8.2.2 Search vendor "Oracle" for product "Communications Session Report Manager" and version " >= 8.2.0 <= 8.2.2"		-		Affected
Oracle Search vendor "Oracle"		Communications Session Route Manager Search vendor "Oracle" for product "Communications Session Route Manager"				>= 8.2.0 <= 8.2.2 Search vendor "Oracle" for product "Communications Session Route Manager" and version " >= 8.2.0 <= 8.2.2"		-		Affected
Oracle Search vendor "Oracle"		Enterprise Manager Ops Center Search vendor "Oracle" for product "Enterprise Manager Ops Center"				12.4.0.0 Search vendor "Oracle" for product "Enterprise Manager Ops Center" and version "12.4.0.0"		-		Affected
Oracle Search vendor "Oracle"		Hyperion Infrastructure Technology Search vendor "Oracle" for product "Hyperion Infrastructure Technology"				11.1.2.4 Search vendor "Oracle" for product "Hyperion Infrastructure Technology" and version "11.1.2.4"		-		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"		Zfs Storage Appliance Kit Search vendor "Oracle" for product "Zfs Storage Appliance Kit"				8.8 Search vendor "Oracle" for product "Zfs Storage Appliance Kit" and version "8.8"		-		Affected