Security readout for executives and security teams
Plain-English summary
This flaw can let a malicious PDF run code on a user's computer if the user opens it in an affected Adobe Acrobat Reader version. The code runs with that user's permissions, so business impact depends on the user's access and endpoint controls.
Executive priority
Treat this as a high-priority endpoint patching issue. It is not documented as actively exploited in the supplied sources, but arbitrary code execution through user-opened documents is a credible business risk.
Technical view
CVE-2021-28560 is a CWE-122 heap-based buffer overflow in Adobe Acrobat Reader DC. A remote unauthenticated attacker can achieve arbitrary code execution in the current user context, but exploitation requires user interaction. CVSS v3.1 is 8.8 high.
Likely exposure
Likely exposure is on endpoints running Acrobat Reader DC 2021.001.20150 or earlier, 2020.001.30020 or earlier, or 2017.011.30194 or earlier. This is a client-side document handling risk, not a server service exposure.
Exploitation context
The provided sources do not identify active exploitation, and the CVE is not marked KEV. The attack path requires a victim to open a malicious file, making phishing, email attachments, shared files, and downloaded PDFs the relevant exposure channels.
Researcher notes
Evidence is limited to the CVE record and Adobe advisory reference. The sources establish affected version thresholds, heap overflow class, user interaction requirement, and current-user code execution impact. They do not provide exploit maturity, proof-of-concept status, or detailed remediation text in the bundle.
Mitigation direction
- Review Adobe APSB21-29 and apply the vendor-recommended Acrobat Reader update.
- Prioritize affected Reader installations on high-privilege and high-value user workstations.
- Reduce exposure to untrusted PDFs from email, web downloads, and shared repositories.
- Use endpoint protection and least-privilege controls to limit post-execution impact.
Validation and detection
- Inventory Acrobat Reader versions across managed endpoints.
- Confirm no installations remain at or below the affected version thresholds.
- Verify remediation status against Adobe APSB21-29 guidance.
- Review email and endpoint telemetry for suspicious PDF delivery or execution patterns.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-122: Exact CWE lookup
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Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-28560 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H2.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.8HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://helpx.adobe.com/security/products/acrobat/apsb21-29.htmlCVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Heap-based Buffer Overflow
Heap-based Buffer Overflow represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.