CVE-2021-39846 Explained : Impact and Mitigation
Learn about CVE-2021-39846 affecting Adobe Acrobat Reader. Understand the vulnerability, its impact, affected versions, and mitigation steps to enhance security.
Adobe Acrobat Reader DC versions 2021.005.20060 (and earlier), 2020.004.30006 (and earlier), and 2017.011.30199 (and earlier) are affected by a stack overflow vulnerability due to insecure handling of crafted PDF files, potentially leading to memory corruption. This article provides an in-depth overview of the CVE-2021-39846 vulnerability.
Understanding CVE-2021-39846
CVE-2021-39846, titled 'Adobe Acrobat Reader /Parent Property Recursive Stack Overflow,' was published on September 14, 2021, with a base CVSS score of 6.1.
What is CVE-2021-39846?
The CVE-2021-39846 vulnerability affects Adobe Acrobat Reader versions through 2021.005.20060, 2020.004.30006, and 2017.011.30199. The vulnerability stems from a stack overflow issue related to the handling of specially crafted PDF files.
The Impact of CVE-2021-39846
The impact of CVE-2021-39846 includes:
- Attack Complexity: Low
- Attack Vector: Local
- Availability Impact: High
- Base Score: 6.1 (Medium)
- User Interaction: Required
- Scope: Unchanged
Technical Details of CVE-2021-39846
Adobe Acrobat Reader's CVE-2021-39846 vulnerability can be understood through the following technical details:
Vulnerability Description
The vulnerability involves a stack-based buffer overflow (CWE-121) due to improper handling of crafted PDF files.
Affected Systems and Versions
The following versions of Acrobat Reader are affected:
- Acrobat Reader DC 2021.005.20060 and earlier
- Acrobat Reader DC 2020.004.30006 and earlier
- Acrobat Reader DC 2017.011.30199 and earlier
Exploitation Mechanism
For exploitation, a victim must open a specially crafted PDF file in Acrobat Reader, requiring user interaction.
Mitigation and Prevention
To mitigate the CVE-2021-39846 vulnerability, consider the following measures:
Immediate Steps to Take
- Update Adobe Acrobat Reader to the latest version.
- Be cautious when opening PDF files from untrusted sources.
Long-Term Security Practices
- Regularly update software and apply security patches.
- Educate users about safe browsing habits.
Patching and Updates
Ensure timely installation of security updates released by Adobe to address vulnerabilities like CVE-2021-39846.