CVE-2021-23017

Nginx 1.20.0 - Denial of Service (DOS)

Severity Score

7.7

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

A security issue in nginx resolver was identified, which might allow an attacker who is able to forge UDP packets from the DNS server to cause 1-byte memory overwrite, resulting in worker process crash or potential other impact.

Se identificó un problema de seguridad en el solucionador de nginx, que podría permitir a un atacante que pueda falsificar paquetes UDP desde el servidor DNS para causar una sobrescritura de memoria de 1 byte, lo que causaría un bloqueo del proceso de trabajo u otro impacto potencial

A flaw was found in nginx. An off-by-one error while processing DNS responses allows a network attacker to write a dot character out of bounds in a heap allocated buffer which can allow overwriting the least significant byte of next heap chunk metadata likely leading to a remote code execution in certain circumstances. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

Nginx version 1.20.0 suffers from a denial of service vulnerability.

*Credits: N/A

CVSS Scores

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

Low

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Attack Vector

Network

Attack Complexity

Medium

Authentication

None

Confidentiality

Partial

Integrity

Partial

Availability

Partial

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2021-01-06 CVE Reserved
2021-05-26 CVE Published
2022-07-11 First Exploit
2024-08-03 CVE Updated
2024-11-21 EPSS Updated
---------- Exploited in Wild
---------- KEV Due Date

CWE

CWE-193: Off-by-one Error

CAPEC

References (20)

URL	Tag	Source
http://packetstormsecurity.com/files/167720/Nginx-1.20.0-Denial-Of-Service.html	Third Party Advisory
https://lists.apache.org/thread.html/r37e6b2165f7c910d8e15fd54f4697857619ad2625f56583802004009%40%3Cnotifications.apisix.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/r4d4966221ca399ce948ef34884652265729d7d9ef8179c78d7f17e7f%40%3Cnotifications.apisix.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/r6fc5c57b38e93e36213e9a18c8a4e5dbd5ced1c7e57f08a1735975ba%40%3Cnotifications.apisix.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/rf232eecd47fdc44520192810560303073cefd684b321f85e311bad31%40%3Cnotifications.apisix.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/rf318aeeb4d7a3a312734780b47de83cefb7e6995da0b2cae5c28675c%40%3Cnotifications.apisix.apache.org%3E	Mailing List
https://security.netapp.com/advisory/ntap-20210708-0006	Third Party Advisory
https://support.f5.com/csp/article/K12331123%2C	X_refsource_misc

URL	Date	SRC
https://www.exploit-db.com/exploits/50973	2022-07-11
https://github.com/M507/CVE-2021-23017-PoC	2023-11-12
https://github.com/ShivamDey/CVE-2021-23017	2023-10-21
https://github.com/lakshit1212/CVE-2021-23017-PoC	2023-07-20

URL	Date	SRC
http://mailman.nginx.org/pipermail/nginx-announce/2021/000300.html	2023-11-07
https://www.oracle.com/security-alerts/cpuapr2022.html	2023-11-07
https://www.oracle.com/security-alerts/cpujan2022.html	2023-11-07
https://www.oracle.com/security-alerts/cpuoct2021.html	2023-11-07

URL	Date	SRC
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7SFVYHC7OXTEO4SMBWXDVK6E5IMEYMEE	2023-11-07
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GNKOP2JR5L7KCIZTJRZDCUPJTUONMC5I	2023-11-07
https://access.redhat.com/security/cve/CVE-2021-23017	2022-01-31
https://bugzilla.redhat.com/show_bug.cgi?id=1963121	2022-01-31

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
F5 Search vendor "F5"		Nginx Search vendor "F5" for product "Nginx"				>= 0.6.18 < 1.20.1 Search vendor "F5" for product "Nginx" and version " >= 0.6.18 < 1.20.1"		-		Affected
Openresty Search vendor "Openresty"		Openresty Search vendor "Openresty" for product "Openresty"				< 1.19.3.2 Search vendor "Openresty" for product "Openresty" and version " < 1.19.3.2"		-		Affected
Fedoraproject Search vendor "Fedoraproject"		Fedora Search vendor "Fedoraproject" for product "Fedora"				33 Search vendor "Fedoraproject" for product "Fedora" and version "33"		-		Affected
Fedoraproject Search vendor "Fedoraproject"		Fedora Search vendor "Fedoraproject" for product "Fedora"				34 Search vendor "Fedoraproject" for product "Fedora" and version "34"		-		Affected
Netapp Search vendor "Netapp"		Ontap Select Deploy Administration Utility Search vendor "Netapp" for product "Ontap Select Deploy Administration Utility"				-		-		Affected
Oracle Search vendor "Oracle"		Blockchain Platform Search vendor "Oracle" for product "Blockchain Platform"				< 21.1.2 Search vendor "Oracle" for product "Blockchain Platform" and version " < 21.1.2"		-		Affected
Oracle Search vendor "Oracle"		Communications Control Plane Monitor Search vendor "Oracle" for product "Communications Control Plane Monitor"				3.4 Search vendor "Oracle" for product "Communications Control Plane Monitor" and version "3.4"		-		Affected
Oracle Search vendor "Oracle"		Communications Control Plane Monitor Search vendor "Oracle" for product "Communications Control Plane Monitor"				4.2 Search vendor "Oracle" for product "Communications Control Plane Monitor" and version "4.2"		-		Affected
Oracle Search vendor "Oracle"		Communications Control Plane Monitor Search vendor "Oracle" for product "Communications Control Plane Monitor"				4.3 Search vendor "Oracle" for product "Communications Control Plane Monitor" and version "4.3"		-		Affected
Oracle Search vendor "Oracle"		Communications Control Plane Monitor Search vendor "Oracle" for product "Communications Control Plane Monitor"				4.4 Search vendor "Oracle" for product "Communications Control Plane Monitor" and version "4.4"		-		Affected
Oracle Search vendor "Oracle"		Communications Fraud Monitor Search vendor "Oracle" for product "Communications Fraud Monitor"				>= 3.4 <= 4.4 Search vendor "Oracle" for product "Communications Fraud Monitor" and version " >= 3.4 <= 4.4"		-		Affected
Oracle Search vendor "Oracle"		Communications Operations Monitor Search vendor "Oracle" for product "Communications Operations Monitor"				3.4 Search vendor "Oracle" for product "Communications Operations Monitor" and version "3.4"		-		Affected
Oracle Search vendor "Oracle"		Communications Operations Monitor Search vendor "Oracle" for product "Communications Operations Monitor"				4.2 Search vendor "Oracle" for product "Communications Operations Monitor" and version "4.2"		-		Affected
Oracle Search vendor "Oracle"		Communications Operations Monitor Search vendor "Oracle" for product "Communications Operations Monitor"				4.3 Search vendor "Oracle" for product "Communications Operations Monitor" and version "4.3"		-		Affected
Oracle Search vendor "Oracle"		Communications Operations Monitor Search vendor "Oracle" for product "Communications Operations Monitor"				4.4 Search vendor "Oracle" for product "Communications Operations Monitor" and version "4.4"		-		Affected
Oracle Search vendor "Oracle"		Communications Session Border Controller Search vendor "Oracle" for product "Communications Session Border Controller"				8.4 Search vendor "Oracle" for product "Communications Session Border Controller" and version "8.4"		-		Affected
Oracle Search vendor "Oracle"		Communications Session Border Controller Search vendor "Oracle" for product "Communications Session Border Controller"				9.0 Search vendor "Oracle" for product "Communications Session Border Controller" and version "9.0"		-		Affected
Oracle Search vendor "Oracle"		Enterprise Communications Broker Search vendor "Oracle" for product "Enterprise Communications Broker"				3.3.0 Search vendor "Oracle" for product "Enterprise Communications Broker" and version "3.3.0"		-		Affected
Oracle Search vendor "Oracle"		Enterprise Session Border Controller Search vendor "Oracle" for product "Enterprise Session Border Controller"				8.4 Search vendor "Oracle" for product "Enterprise Session Border Controller" and version "8.4"		-		Affected
Oracle Search vendor "Oracle"		Enterprise Session Border Controller Search vendor "Oracle" for product "Enterprise Session Border Controller"				9.0 Search vendor "Oracle" for product "Enterprise Session Border Controller" and version "9.0"		-		Affected
Oracle Search vendor "Oracle"		Enterprise Telephony Fraud Monitor Search vendor "Oracle" for product "Enterprise Telephony Fraud Monitor"				3.4 Search vendor "Oracle" for product "Enterprise Telephony Fraud Monitor" and version "3.4"		-		Affected
Oracle Search vendor "Oracle"		Enterprise Telephony Fraud Monitor Search vendor "Oracle" for product "Enterprise Telephony Fraud Monitor"				4.2 Search vendor "Oracle" for product "Enterprise Telephony Fraud Monitor" and version "4.2"		-		Affected
Oracle Search vendor "Oracle"		Enterprise Telephony Fraud Monitor Search vendor "Oracle" for product "Enterprise Telephony Fraud Monitor"				4.3 Search vendor "Oracle" for product "Enterprise Telephony Fraud Monitor" and version "4.3"		-		Affected
Oracle Search vendor "Oracle"		Enterprise Telephony Fraud Monitor Search vendor "Oracle" for product "Enterprise Telephony Fraud Monitor"				4.4 Search vendor "Oracle" for product "Enterprise Telephony Fraud Monitor" and version "4.4"		-		Affected
Oracle Search vendor "Oracle"		Goldengate Search vendor "Oracle" for product "Goldengate"				< 21.4.0.0.0 Search vendor "Oracle" for product "Goldengate" and version " < 21.4.0.0.0"		-		Affected