Arbitrary code execution via heap buffer overflow
Published Feb 11, 2021 · Updated Oct 21, 2025
Heap-based buffer overflow in Adobe Acrobat Reader allows remote attackers to execute code through a malicious file. Adobe identifies malicious-file handling as the trigger but has not disclosed the parser, malformed field, or memory operation that overflows the heap. A user must open the file; code runs with that user's privileges in Continuous 2020.013.20074 and earlier, Classic 2020 2020.001.30018 and earlier, and Classic 2017 2017.011.30188 and earlier on Windows and macOS.
Summary
What happened
Heap-based buffer overflow in Adobe Acrobat Reader allows remote attackers to execute code through a malicious file. Adobe identifies malicious-file handling as the trigger but has not disclosed the parser, malformed field, or memory operation that overflows the heap. A user must open the file; code runs with that user's privileges in Continuous 2020.013.20074 and earlier, Classic 2020 2020.001.30018 and earlier, and Classic 2017 2017.011.30188 and earlier on Windows and macOS.
The record
- CVE
- CVE-2021-21017
- Published
- Feb 11, 2021
- Updated
- Oct 21, 2025
- Vendor
- Adobe
- Product
- Adobe Acrobat Reader
- Classifications
- CWE-122, CWE-787, T1204.002, T1203
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Feb 11, 2021CVE publishedPublication date reported by the CVE source.
- Nov 3, 2021Exploitation reportedCISA Known Exploited Vulnerabilities Catalog entry
- Oct 21, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=unspecified <=2017.011.30188
- Affected versionversion=unspecified <=2020.001.30018
- Affected versionversion=unspecified <=2020.013.20074
- Affected versionversion=unspecified <=None
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Reported exploitation
- CISA Known Exploited Vulnerabilities Catalog entryknown exploited catalog
- Limited attacks targeting Adobe Reader on Windowsreported exploitation
Technologies
Your stack
See the directory against your own environment.
Your stack
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