CVE-2021-39843 : Security Advisory and Response
Learn about CVE-2021-39843, a critical out-of-bounds write vulnerability in Adobe Acrobat Reader DC. Understand the impact, affected versions, and mitigation steps to secure your system.
Adobe Acrobat Reader XObject Out-of-Bound Write Vulnerability
Understanding CVE-2021-39843
Acrobat Reader DC versions 2021.005.20060 and earlier are affected by a critical out-of-bounds write vulnerability with a high CVSS score.
What is CVE-2021-39843?
- Vulnerability Type: Out-of-bounds Write (CWE-787)
- Attack Complexity: Low
- Attack Vector: Local
- User Interaction Required: Yes
- Impact: High severity with potential arbitrary code execution
The Impact of CVE-2021-39843
The vulnerability could allow an attacker to execute arbitrary code on the system, posing risks of information disclosure and integrity compromise.
Technical Details of CVE-2021-39843
Acrobat Reader DC versions are susceptible to this vulnerability.
Vulnerability Description
- Affected Versions: DC 2021 July, 20.0-Classic 2021 July, 17.0-Classic 2021 July
- Exploitation: Requires user interaction via opening a malicious file
Affected Systems and Versions
- Product: Acrobat Reader
- Vendor: Adobe
Exploitation Mechanism
The vulnerability allows out-of-bounds write access leading to potential code execution under the current user's context.
Mitigation and Prevention
Immediate action and long-term security practices are crucial.
Immediate Steps to Take
- Update Acrobat Reader to the latest version
- Exercise caution when opening files from untrusted sources
Long-Term Security Practices
- Regularly update software and security patches
- Implement user awareness training on safe browsing habits
Patching and Updates
- Refer to Adobe's security advisory for specific patching guidance and updates