Security readout for executives and security teams
Plain-English summary
CVE-2021-39831 affects Adobe FrameMaker when opening a malicious PDF. If exploited, code could run with the victim user's privileges. The business risk is highest where FrameMaker users receive external PDFs or handle untrusted documents.
Executive priority
Treat as a high-priority workstation patching issue, not an internet-facing emergency. Prioritize teams that receive external PDFs or use FrameMaker for customer, supplier, or publishing workflows.
Technical view
The issue is a CWE-787 out-of-bounds write in Adobe FrameMaker PDF file parsing. Affected versions are FrameMaker 2019 Update 8 and earlier, and FrameMaker 2020 Release Update 2 and earlier. CVSS 3.1 is 7.8, requiring local user interaction but no privileges.
Likely exposure
Exposure is limited to systems with affected Adobe FrameMaker versions installed, especially workstations used for document authoring or PDF intake. The source bundle does not identify server-side exposure.
Exploitation context
The CVE requires a victim to open a malicious PDF file. The provided sources do not state active exploitation, and the CVE is not listed as KEV in the bundle.
Researcher notes
Key constraints are user interaction, malicious PDF delivery, and execution in the current user context. The bundle provides no exploit details, no KEV evidence, and no public exploitation claim.
Mitigation direction
- Review Adobe APSB21-74 and apply vendor-recommended FrameMaker updates.
- Inventory FrameMaker installations and prioritize externally exposed document-handling teams.
- Restrict opening untrusted PDFs in FrameMaker until affected systems are updated.
- Run FrameMaker under least-privilege user accounts.
- Use email and endpoint controls to reduce malicious PDF delivery risk.
Validation and detection
- Check installed FrameMaker versions against the affected version ranges.
- Confirm FrameMaker 2019 systems are later than Update 8.
- Confirm FrameMaker 2020 systems are later than Release Update 2.
- Review endpoint telemetry for suspicious FrameMaker child processes.
- Verify users handling external PDFs received the vendor update.
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-787: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
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-2021-39831 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
- 7.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/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:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H1.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.8HighVector: CVSS:3.1/AV:L/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/framemaker/apsb21-74.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.
Out-of-bounds Write
Out-of-bounds Write represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.