CVE-2021-39837

Adobe Acrobat Reader DC AcroForm deleteItemAt Use-After-Free Remote Code Execution Vulnerability

Severity Score

7.8

*CVSS v3

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

Acrobat Reader DC versions 2021.005.20060 (and earlier), 2020.004.30006 (and earlier) and 2017.011.30199 (and earlier) are affected by a use-after-free vulnerability in the processing of the AcroForm deleteItemAt action that could result in arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.

Acrobat Reader DC versiones 2021.005.20060 (y anteriores), versiones 2020.004.30006 (y anteriores), y versiones 2017.011.30199 (y anteriores), están afectadas por una vulnerabilidad de uso de memoria previamente liberada en el procesamiento de la acción deleteItemAt de AcroForm que podría resultar en una ejecución de código arbitrario en el contexto del usuario actual. Es requerida una interacción del usuario para explotar este problema, ya que la víctima debe abrir un archivo malicioso

This vulnerability allows remote attackers to execute arbitrary code on affected installations of Adobe Acrobat Reader DC. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.
The specific flaw exists within the handling of AcroForm fields. The issue results from the lack of validating the existence of an object prior to performing operations on the object. An attacker can leverage this vulnerability to execute code in the context of the current process.

*Credits: Mark Vincent Yason (@MarkYason)

Attack Vector

Local

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

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

2021-08-23 CVE Reserved
2021-09-16 CVE Published
2024-09-16 CVE Updated
2024-11-01 EPSS Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-416: Use After Free

CAPEC

References (1)

URL	Tag	Source

URL	Date	SRC

URL	Date	SRC

URL	Date	SRC
https://helpx.adobe.com/security/products/acrobat/apsb21-55.html	2023-11-07

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Adobe Search vendor "Adobe"	Acrobat Search vendor "Adobe" for product "Acrobat"	>= 20.001.30005 <= 20.004.30006 Search vendor "Adobe" for product "Acrobat" and version " >= 20.001.30005 <= 20.004.30006"	classic	Affected	in	Apple Search vendor "Apple"	Macos Search vendor "Apple" for product "Macos"	-	-	Safe
Adobe Search vendor "Adobe"	Acrobat Search vendor "Adobe" for product "Acrobat"	>= 20.001.30005 <= 20.004.30006 Search vendor "Adobe" for product "Acrobat" and version " >= 20.001.30005 <= 20.004.30006"	classic	Affected	in	Microsoft Search vendor "Microsoft"	Windows Search vendor "Microsoft" for product "Windows"	-	-	Safe
Adobe Search vendor "Adobe"	Acrobat Reader Search vendor "Adobe" for product "Acrobat Reader"	>= 20.001.30005 <= 20.004.30006 Search vendor "Adobe" for product "Acrobat Reader" and version " >= 20.001.30005 <= 20.004.30006"	classic	Affected	in	Apple Search vendor "Apple"	Macos Search vendor "Apple" for product "Macos"	-	-	Safe
Adobe Search vendor "Adobe"	Acrobat Reader Search vendor "Adobe" for product "Acrobat Reader"	>= 20.001.30005 <= 20.004.30006 Search vendor "Adobe" for product "Acrobat Reader" and version " >= 20.001.30005 <= 20.004.30006"	classic	Affected	in	Microsoft Search vendor "Microsoft"	Windows Search vendor "Microsoft" for product "Windows"	-	-	Safe
Adobe Search vendor "Adobe"	Acrobat Dc Search vendor "Adobe" for product "Acrobat Dc"	>= 15.008.20082 <= 21.005.20058 Search vendor "Adobe" for product "Acrobat Dc" and version " >= 15.008.20082 <= 21.005.20058"	continuous	Affected	in	Apple Search vendor "Apple"	Macos Search vendor "Apple" for product "Macos"	-	-	Safe
Adobe Search vendor "Adobe"	Acrobat Reader Dc Search vendor "Adobe" for product "Acrobat Reader Dc"	>= 15.008.20082 <= 21.005.20058 Search vendor "Adobe" for product "Acrobat Reader Dc" and version " >= 15.008.20082 <= 21.005.20058"	continuous	Affected	in	Apple Search vendor "Apple"	Macos Search vendor "Apple" for product "Macos"	-	-	Safe
Adobe Search vendor "Adobe"	Acrobat Dc Search vendor "Adobe" for product "Acrobat Dc"	>= 15.008.20082 <= 21.005.20060 Search vendor "Adobe" for product "Acrobat Dc" and version " >= 15.008.20082 <= 21.005.20060"	continuous	Affected	in	Microsoft Search vendor "Microsoft"	Windows Search vendor "Microsoft" for product "Windows"	-	-	Safe
Adobe Search vendor "Adobe"	Acrobat Reader Dc Search vendor "Adobe" for product "Acrobat Reader Dc"	>= 15.008.20082 <= 21.005.20060 Search vendor "Adobe" for product "Acrobat Reader Dc" and version " >= 15.008.20082 <= 21.005.20060"	continuous	Affected	in	Microsoft Search vendor "Microsoft"	Windows Search vendor "Microsoft" for product "Windows"	-	-	Safe
Adobe Search vendor "Adobe"	Acrobat Search vendor "Adobe" for product "Acrobat"	>= 17.011.30059 <= 17.011.30199 Search vendor "Adobe" for product "Acrobat" and version " >= 17.011.30059 <= 17.011.30199"	classic	Affected	in	Apple Search vendor "Apple"	Macos Search vendor "Apple" for product "Macos"	-	-	Safe
Adobe Search vendor "Adobe"	Acrobat Search vendor "Adobe" for product "Acrobat"	>= 17.011.30059 <= 17.011.30199 Search vendor "Adobe" for product "Acrobat" and version " >= 17.011.30059 <= 17.011.30199"	classic	Affected	in	Microsoft Search vendor "Microsoft"	Windows Search vendor "Microsoft" for product "Windows"	-	-	Safe
Adobe Search vendor "Adobe"	Acrobat Reader Search vendor "Adobe" for product "Acrobat Reader"	>= 17.011.30059 <= 17.011.30199 Search vendor "Adobe" for product "Acrobat Reader" and version " >= 17.011.30059 <= 17.011.30199"	classic	Affected	in	Apple Search vendor "Apple"	Macos Search vendor "Apple" for product "Macos"	-	-	Safe
Adobe Search vendor "Adobe"	Acrobat Reader Search vendor "Adobe" for product "Acrobat Reader"	>= 17.011.30059 <= 17.011.30199 Search vendor "Adobe" for product "Acrobat Reader" and version " >= 17.011.30059 <= 17.011.30199"	classic	Affected	in	Microsoft Search vendor "Microsoft"	Windows Search vendor "Microsoft" for product "Windows"	-	-	Safe