Arbitrary code execution via AcroForm use-after-free
Published Sep 29, 2021 · Updated Sep 17, 2024
Use-after-free in Adobe Acrobat Reader DC through July 2021 allows attackers to execute arbitrary code when a user opens a malicious file. The AcroForm buttonGetCaption action can reference freed memory while processing crafted PDF content, enabling execution in the current user's context. Exploitation requires a victim to open the attacker-supplied document; the record does not require prior authentication, and impact is bounded by the current user's permissions.
Summary
What happened
Use-after-free in Adobe Acrobat Reader DC through July 2021 allows attackers to execute arbitrary code when a user opens a malicious file. The AcroForm buttonGetCaption action can reference freed memory while processing crafted PDF content, enabling execution in the current user's context. Exploitation requires a victim to open the attacker-supplied document; the record does not require prior authentication, and impact is bounded by the current user's permissions.
The record
- CVE
- CVE-2021-39842
- Published
- Sep 29, 2021
- Updated
- Sep 17, 2024
- Vendor
- Adobe
- Product
- Adobe Acrobat Reader
- Classifications
- CWE-416, T1566.001
- 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
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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.
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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