Security readout for executives and security teams
Plain-English summary
Adobe InDesign can be compromised if a user opens a malicious TIF file. Successful exploitation could let attacker-controlled code run with that user's permissions, which can expose files and enable further compromise. The sources do not show active exploitation.
Executive priority
Treat as high priority where InDesign is used, especially on systems handling external creative files. It is not described as wormable, but code execution through a document-open workflow is business-relevant.
Technical view
CVE-2021-39821 is a CWE-125 out-of-bounds read in Adobe InDesign TIF parsing. Affected InDesign versions include 16.3 and earlier, and 16.3.1 and earlier. CVSS is 7.8, with low complexity, no privileges required, and required user interaction.
Likely exposure
Exposure is most likely on workstations running affected Adobe InDesign versions where users receive or open external TIF files. Design, publishing, marketing, and prepress teams are the highest-probability populations.
Exploitation context
Exploitation requires convincing a victim to open a malicious TIF file in InDesign. The provided sources do not cite CISA KEV listing or active exploitation evidence.
Researcher notes
The bundle provides CVE details, CVSS, CWE, affected version text, and an Adobe advisory link, but no CPEs or explicit fixed build details. Do not infer affected products beyond Adobe InDesign.
Mitigation direction
- Identify endpoints with Adobe InDesign installed.
- Compare installed versions against Adobe APSB21-73 guidance.
- Update InDesign according to Adobe's vendor advisory.
- Limit opening untrusted TIF files until patched.
- Use least-privilege user accounts for creative workstations.
Validation and detection
- Inventory Adobe InDesign versions across managed endpoints.
- Confirm whether affected versions remain installed.
- Review email and file-transfer workflows for external TIF exposure.
- Check EDR logs for suspicious activity after TIF file opens.
- Document patch status against Adobe APSB21-73.
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
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CWE-125: 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-2021-39821 mapping review
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Open ATT&CK lookup- Severity
- High
- CVSS
- 7.8 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/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:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H1.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
7.8HighVector: CVSS:3.0/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/indesign/apsb21-73.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 Read
Out-of-bounds Read represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.