Security readout for executives and security teams
Plain-English summary
This flaw lets a malicious audio file trigger memory corruption in Adobe After Effects. An attacker would need a user to open a crafted .m4a file. Successful exploitation could run code with that user’s permissions, making creative workstations and media-review workflows the main concern.
Executive priority
Treat this as a high-priority workstation remediation issue for creative and media teams, not an internet-facing emergency. Prioritize patching systems that handle external files.
Technical view
CVE-2021-40759 affects Adobe After Effects 18.4.1 and earlier. It is a CWE-788 memory corruption issue in .m4a file handling with CVSS 3.1 score 7.8. The vector is local, low complexity, no privileges required, user interaction required, with high confidentiality, integrity, and availability impact.
Likely exposure
Organizations are exposed where Adobe After Effects 18.4.1 or earlier remains installed, especially on systems receiving external media files from clients, vendors, or shared asset pipelines.
Exploitation context
The source bundle does not show CISA KEV listing or confirmed active exploitation. Exploitation requires convincing a victim to open a specially crafted .m4a file in the vulnerable application.
Researcher notes
Available evidence identifies the vulnerable product, version boundary, file type, impact, CVSS vector, and user-interaction requirement. The bundle does not provide exploit details, proof of exploitation, or exact fixed version text.
Mitigation direction
- Inventory Adobe After Effects installations and identify version 18.4.1 or earlier.
- Apply Adobe APSB21-79 guidance and upgrade to the vendor-specified fixed release.
- Restrict opening untrusted .m4a files in After Effects until systems are updated.
- Use endpoint controls to reduce delivery risk from unexpected media attachments.
- Remove or isolate outdated After Effects installations where patching is not available.
Validation and detection
- Confirm installed After Effects versions against Adobe APSB21-79 affected-version scope.
- Verify remediated systems no longer report version 18.4.1 or earlier.
- Review endpoint telemetry for After Effects opening unexpected .m4a files.
- Check external-media handling teams for remaining unpatched workstations.
- Document exceptions and compensating controls for any systems awaiting remediation.
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-788: 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-2021-40759 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/after_effects/apsb21-79.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.
Access of Memory Location After End of Buffer
Access of Memory Location After End of Buffer represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.