CVE-2021-37334

Severity Score

9.8

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

Umbraco Forms version 4.0.0 up to and including 8.7.5 and below are vulnerable to a security flaw that could lead to a remote code execution attack and/or arbitrary file deletion. A vulnerability occurs because validation of the file extension is performed after the file has been stored in a temporary directory. By default, files are stored within the application directory structure at %BASEDIR%/APP_DATA/TEMP/FileUploads/. Whilst access to this directory is restricted by the root web.config file, it is possible to override this restriction by uploading another specially crafted web.config file to the temporary directory. It is possible to exploit this flaw to upload a malicious script file to execute arbitrary code and system commands on the server.

Las versiones de Umbraco Forms 4.0.0 hasta la 8.7.5 e inferiores son vulnerables a un fallo de seguridad que podría dar lugar a un ataque de ejecución remota de código y/o eliminación arbitraria de archivos. La vulnerabilidad se produce porque la validación de la extensión del archivo se realiza después de que el archivo se haya almacenado en un directorio temporal. Por defecto, los archivos se almacenan dentro de la estructura de directorios de la aplicación en %BASEDIR%/APP_DATA/TEMP/FileUploads/. Aunque el acceso a este directorio está restringido por el archivo web.config raíz, es posible anular esta restricción cargando otro archivo web.config especialmente diseñado en el directorio temporal. Es posible explotar este fallo para subir un archivo de script malicioso para ejecutar código arbitrario y comandos del sistema en el servidor

*Credits: N/A

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Attack Vector

Network

Attack Complexity

Medium

Authentication

None

Confidentiality

Complete

Integrity

Complete

Availability

Complete

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2021-07-21 CVE Reserved
2021-08-25 CVE Published
2024-08-04 CVE Updated
2024-10-26 EPSS Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CAPEC

References (2)

URL	Tag	Source

URL	Date	SRC

URL	Date	SRC
https://umbraco.com/blog/security-advisory-20th-of-july-2021-patch-is-now-available	2021-11-28

URL	Date	SRC
https://umbraco.com/blog/security-advisory-security-patches-for-umbraco-forms-ready-on-july-20th-2021-at-7-am-utc	2021-11-28

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Umbraco Search vendor "Umbraco"		Forms Search vendor "Umbraco" for product "Forms"				>= 4.0.0 < 4.4.9 Search vendor "Umbraco" for product "Forms" and version " >= 4.0.0 < 4.4.9"		-		Affected
Umbraco Search vendor "Umbraco"		Forms Search vendor "Umbraco" for product "Forms"				>= 6.0.0 < 6.0.10 Search vendor "Umbraco" for product "Forms" and version " >= 6.0.0 < 6.0.10"		-		Affected
Umbraco Search vendor "Umbraco"		Forms Search vendor "Umbraco" for product "Forms"				>= 7.0.0 < 7.0.7 Search vendor "Umbraco" for product "Forms" and version " >= 7.0.0 < 7.0.7"		-		Affected
Umbraco Search vendor "Umbraco"		Forms Search vendor "Umbraco" for product "Forms"				>= 7.1.0 < 7.1.4 Search vendor "Umbraco" for product "Forms" and version " >= 7.1.0 < 7.1.4"		-		Affected
Umbraco Search vendor "Umbraco"		Forms Search vendor "Umbraco" for product "Forms"				>= 7.2.0 < 7.2.1 Search vendor "Umbraco" for product "Forms" and version " >= 7.2.0 < 7.2.1"		-		Affected
Umbraco Search vendor "Umbraco"		Forms Search vendor "Umbraco" for product "Forms"				>= 7.3.0 < 7.3.2 Search vendor "Umbraco" for product "Forms" and version " >= 7.3.0 < 7.3.2"		-		Affected
Umbraco Search vendor "Umbraco"		Forms Search vendor "Umbraco" for product "Forms"				>= 7.4.0 < 7.4.3 Search vendor "Umbraco" for product "Forms" and version " >= 7.4.0 < 7.4.3"		-		Affected
Umbraco Search vendor "Umbraco"		Forms Search vendor "Umbraco" for product "Forms"				>= 7.5.0 < 7.5.4 Search vendor "Umbraco" for product "Forms" and version " >= 7.5.0 < 7.5.4"		-		Affected
Umbraco Search vendor "Umbraco"		Forms Search vendor "Umbraco" for product "Forms"				>= 8.0.0 < 8.0.2 Search vendor "Umbraco" for product "Forms" and version " >= 8.0.0 < 8.0.2"		-		Affected
Umbraco Search vendor "Umbraco"		Forms Search vendor "Umbraco" for product "Forms"				>= 8.1.0 < 8.1.6 Search vendor "Umbraco" for product "Forms" and version " >= 8.1.0 < 8.1.6"		-		Affected
Umbraco Search vendor "Umbraco"		Forms Search vendor "Umbraco" for product "Forms"				>= 8.2.0 < 8.2.3 Search vendor "Umbraco" for product "Forms" and version " >= 8.2.0 < 8.2.3"		-		Affected
Umbraco Search vendor "Umbraco"		Forms Search vendor "Umbraco" for product "Forms"				>= 8.3.0 < 8.3.4 Search vendor "Umbraco" for product "Forms" and version " >= 8.3.0 < 8.3.4"		-		Affected
Umbraco Search vendor "Umbraco"		Forms Search vendor "Umbraco" for product "Forms"				>= 8.4.0 < 8.4.4 Search vendor "Umbraco" for product "Forms" and version " >= 8.4.0 < 8.4.4"		-		Affected
Umbraco Search vendor "Umbraco"		Forms Search vendor "Umbraco" for product "Forms"				>= 8.5.0 < 8.5.7 Search vendor "Umbraco" for product "Forms" and version " >= 8.5.0 < 8.5.7"		-		Affected
Umbraco Search vendor "Umbraco"		Forms Search vendor "Umbraco" for product "Forms"				>= 8.6.0 < 8.6.2 Search vendor "Umbraco" for product "Forms" and version " >= 8.6.0 < 8.6.2"		-		Affected
Umbraco Search vendor "Umbraco"		Forms Search vendor "Umbraco" for product "Forms"				>= 8.7.0 < 8.7.6 Search vendor "Umbraco" for product "Forms" and version " >= 8.7.0 < 8.7.6"		-		Affected