CVE-2021-39850 : What You Need to Know
Learn about CVE-2021-39850, a medium-severity vulnerability in Adobe Acrobat Reader DC that could lead to application denial-of-service. Take immediate steps to update and secure affected systems.
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 Null pointer dereference vulnerability. An unauthenticated attacker could leverage this vulnerability to achieve an application denial-of-service in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.
Understanding CVE-2021-39850
Acrobat Reader DC versions are prone to a Null pointer dereference vulnerability that could lead to application denial-of-service threats.
What is CVE-2021-39850?
CVE-2021-39850 is a vulnerability in Adobe Acrobat Reader DC that allows unauthenticated attackers to trigger a null pointer dereference, leading to an application denial-of-service scenario.
The Impact of CVE-2021-39850
This vulnerability has the following impact:
- CVSS Base Score: 5.5 (Medium)
- Attack Vector: Local
- Attack Complexity: Low
- User Interaction: Required
- Availability Impact: High
- Scope: Unchanged
- No Confidentiality or Integrity Impact
Technical Details of CVE-2021-39850
Adobe Acrobat Reader DC vulnerability details and affected systems.
Vulnerability Description
The vulnerability is a NULL Pointer Dereference (CWE-476) that could be exploited by an unauthenticated attacker to cause an application denial-of-service, requiring the victim to open a malicious file.
Affected Systems and Versions
The following versions of Acrobat Reader are affected:
- DC 2021 July and earlier
- 20.0-Classic 2021 July and earlier
- 17.0-Classic 2021 July and earlier
- None specified
Exploitation Mechanism
To exploit this vulnerability, an attacker would need to trick a victim into opening a specially crafted malicious file, triggering the NULL Pointer Dereference.
Mitigation and Prevention
Steps to mitigate and prevent the CVE-2021-39850 vulnerability.
Immediate Steps to Take
Immediate actions to enhance security:
- Update Acrobat Reader to the latest patched version.
- Be cautious while opening files from untrusted sources.
Long-Term Security Practices
Best long-term security practices:
- Regularly update software to patch known vulnerabilities.
- Educate users on safe file handling and cybersecurity awareness.
Patching and Updates
To address CVE-2021-39850, it is crucial to:
- Install the latest security updates provided by Adobe.