Code execution via out-of-bounds write
Published Sep 29, 2021 · Updated Sep 17, 2024
Out-of-bounds write in Adobe Acrobat Reader 2017, 2020, and DC allows context-dependent attackers to execute code through a malicious PDF. Adobe has not disclosed the affected parser locus or the exact operation that writes beyond its intended memory boundary. Exploitation requires a victim to open the crafted file, after which code runs with the current user's privileges.
Summary
What happened
Out-of-bounds write in Adobe Acrobat Reader 2017, 2020, and DC allows context-dependent attackers to execute code through a malicious PDF. Adobe has not disclosed the affected parser locus or the exact operation that writes beyond its intended memory boundary. Exploitation requires a victim to open the crafted file, after which code runs with the current user's privileges.
The record
- CVE
- CVE-2021-39843
- Published
- Sep 29, 2021
- Updated
- Sep 17, 2024
- Vendor
- Adobe
- Product
- Adobe Acrobat Reader
- Classifications
- CWE-787, T1566.001, T1204.002
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 29, 2021CVE publishedPublication date reported by the CVE source.
- Sep 17, 2024Record 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 <=17.0-Classic 2021 July
- Affected versionversion=unspecified <=20.0-Classic 2021 July
- Affected versionversion=unspecified <=DC 2021 July
- Affected versionversion=unspecified <=None
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
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.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo