Acrobat
CVE-2021-39853
MEDIUM
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A10:2025 - Mishandling of Exceptional Conditions
ASVS 5.0
V16 - Security Logging and Error Handling Null pointer safety, defensive checks
MITRE ATT&CK
1 technique across 1 tactic: Impact The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS score of 5.5 (MEDIUM). Attack characteristics: local attack vector, low complexity, no privileges required, user interaction required. |
| Exploit ScenarioDerived | A local attacker with access to the system could crash the application by dereferencing a null pointer. No authentication is required to exploit this vulnerability. |
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Alert meAnalysisAI
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. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
RemediationAI
No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Check pointers before dereferencing. Use static analysis tools to detect null pointer paths.
Affects your stack
Find out whether the stacks and servers you run are on an affected version.
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
This vulnerability is classified as NULL Pointer Dereference (CWE-476), which allows attackers to crash the application by dereferencing a null pointer. 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. Affected products include: Adobe Acrobat Dc, Adobe Acrobat Reader Dc, Adobe Acrobat, Adobe Acrobat Reader.
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionNVD
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.
Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
A null pointer dereference occurs when a program attempts to access memory through a pointer that has been set to NULL (address 0x0).
Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.
Affected Products (CPE)NVD
Adobe Flash Player contains a type confusion vulnerability in object handling that allows remote attackers to execute ar
Adobe Reader and Acrobat contain a use-after-free vulnerability in the Doc.media.newPlayer JavaScript method that was ac
Adobe Flash Player 10.2 and earlier across all platforms contain an unspecified vulnerability allowing remote code execu
Integer overflow in Adobe Reader and Acrobat 9.x before 9.5.5, 10.x before 10.1.7, and 11.x before 11.0.03 allows attack
Adobe Reader and Acrobat 9.x before 9.5.4, 10.x before 10.1.6, and 11.x before 11.0.02 allow remote attackers to execute
Buffer overflow in Adobe Reader and Acrobat 9.x before 9.5.4, 10.x before 10.1.6, and 11.x before 11.0.02 allows remote
Buffer overflow in Adobe Reader and Acrobat 9.x before 9.5.5, 10.x before 10.1.7, and 11.x before 11.0.03 allows attacke
Prototype pollution in Adobe Acrobat Reader versions 24.001.30356, 26.001.21367 and earlier enables arbitrary code execu
Adobe Reader and Acrobat 10.x before 10.1.14 and 11.x before 11.0.11 on Windows and OS X allow attackers to bypass inten
Multiple heap-based buffer overflows in Adobe Reader and Acrobat 10.x before 10.1.14 and 11.x before 11.0.11 on Windows
Buffer overflow in Adobe Reader and Acrobat before 10.1.8 and 11.x before 11.0.04 on Windows and Mac OS X allows attacke
Buffer overflow in Adobe Reader and Acrobat before 10.1.8 and 11.x before 11.0.04 on Windows and Mac OS X allows attacke
NVD
CVE.org
EPSS
GitHub PoC
Exploit-DB