CVE-2021-39859 : Exploit Details and Defense Strategies
Learn about CVE-2021-39859, a Use After Free vulnerability in Adobe Acrobat Reader DC versions 2021.005.20060 and earlier. Find details on impact, affected systems, exploitation, and mitigation steps.
This article provides details about the CVE-2021-39859 vulnerability affecting Adobe Acrobat Reader DC.
Understanding CVE-2021-39859
This section dives into the specifics of the Use After Free vulnerability in Adobe Acrobat Reader DC.
What is CVE-2021-39859?
CVE-2021-39859 refers to a Use After Free vulnerability in Adobe Acrobat Reader DC versions 2021.005.20060 and earlier. This flaw could result in the disclosure of sensitive memory, with potential exploitation to bypass mitigations like ASLR by malicious actors. Exploitation necessitates user interaction through the opening of a malicious file.
The Impact of CVE-2021-39859
The vulnerability has a CVSSv3 base score of 5.5, marked as medium severity. Specific impacts include:
- Low attack complexity and vector
- High confidentiality impact
- No integrity and availability impact
- User interaction required for exploitation
Technical Details of CVE-2021-39859
This section outlines the technical aspects of the CVE-2021-39859 vulnerability.
Vulnerability Description
The vulnerability is categorized as a Use After Free (CWE-416) flaw, leading to potential memory disclosure in affected Adobe Acrobat Reader DC versions.
Affected Systems and Versions
- Product: Acrobat Reader
- Vendor: Adobe
- Affected Versions:
- 2021.005.20060 and earlier
- 2020.004.30006 and earlier
- 2017.011.30199 and earlier
Exploitation Mechanism
The exploitation of this vulnerability requires a victim to open a malicious file, subsequently triggering the Use After Free flaw.
Mitigation and Prevention
Insights into addressing and mitigating the impacts of CVE-2021-39859.
Immediate Steps to Take
- Update Adobe Acrobat Reader DC to the latest version
- Be cautious while opening files from untrusted sources
Long-Term Security Practices
- Regularly update software and applications
- Implement security best practices to avoid interacting with suspicious files
Patching and Updates
- Adobe has released a security advisory (APSB21-55) addressing this vulnerability