Background & Context

Adobe Acrobat is a family of application software and Web services developed by Adobe Inc. to view, create, manipulate, print and manage Portable Document Format (PDF) files. The family comprises Acrobat Reader (formerly Reader), Acrobat (formerly Exchange) and Acrobat.com. The basic Acrobat Reader, available for several desktop and mobile platforms, is freeware; it supports viewing, printing, scaling or resizing and annotating of PDF files. It is currently available for Windows, macOS, iOS, and Android users only.

Vulnerability Summary

Multiple versions of Acrobat Reader are affected by an out-of-bounds write vulnerability. Exploitation of this issue requires user interaction in that a victim must open a malicious file.

Impact If Exploited

Exploit could result in arbitrary code execution in the context of the current user. This could permit an attacker to execute malicious code on susceptible systems.

NOTE: This vulnerability has been reported by the CISA (America’s Cyber Defense Agency) to be known to be currently actively exploited in the wild as of 2023-09-15. Remediation should be considered as a high priority in any impacted environments

Affected Product Versions

• Acrobat DC prior to version 23.003.20284
• Acrobat Reader DC prior to version 23.003.20284
• Acrobat 2020 for Mac prior to release 20.005.30516
• Acrobat 2020 for Windows prior to release 20.005.30514
• Acrobat Reader 2020 for Mac prior to release 20.005.30516
• Acrobat Reader 2020 for Windows prior to release 20.005.30514

Remediation

Official Fix & Remediation Guidance

Adobe has released a security update for Adobe Acrobat and Reader for Windows and macOS. This update addresses this critical vulnerability. Customers are advised to upgrade to the latest version of Acrobat Reader.

The latest product versions are available to end users via one of the following methods:

• Users can update their product installations manually by choosing [[code:Help > Check for Updates]].
• The products will update automatically, without requiring user intervention, when updates are detected.
• The full Acrobat Reader installer can be downloaded from the [[https://get.adobe.com/reader|Acrobat Reader Download Center]].

For IT administrators (managed environments):

• Refer to the specific release note version for links to installers.
• Install updates via your preferred methodology, such as AIP-GPO, bootstrapper, SCUP/SCCM (Windows), or on macOS, Apple Remote Desktop and SSH.

NOTE: Remediation of this vulnerability by patching to a specific version indicated may not be sufficient to secure the product against further vulnerabilities discovered in later versions, subsequent to the publication of this guidance. Unless contra-indicated, customers are therefore advised to always upgrade to the latest version of the product available.

Temporary Mitigation & Workarounds

(The vendor has not advised of any alternative temporary mitigation or workarounds)

NOTE: Caution should always be taken in applying any temporary mitigations listed. Mitigations are only recommended in cases where patches to remediate the vulnerability are not available, or cannot safely be applied to a given environment immediately. A given mitigation may not in all cases be recommended officially by the application vendor. The viability of any given temporary mitigation measure may vary, depending on server platform and existing configuration. Mitigations listed may incompletely remediate any given vulnerability. Configuration changes to implement listed mitigations may impact/disrupt required functionality within a given customer application. Care should therefore be taken to carefully analyse any listed mitigations for appropriateness to a given environment. Customers are advised to test any configuration changes prior to their being introduced into a production environment.

References:

• https://helpx.adobe.com/security/products/acrobat/apsb23-34.html

Category: Arbitrary Code Execution

Detection

AppCheck has added a plugin to detect the flaw that will run as part of your standard scans.

About AppCheck

AppCheck is a software security vendor based in the UK, offering a leading security scanning platform that automates the discovery of security flaws within organisations websites, applications, network, and cloud infrastructure. AppCheck are authorized by the Common Vulnerabilities and Exposures (CVE) Program as a CVE Numbering Authority (CNA).