Security readout for executives and security teams
Plain-English summary
This vulnerability affects Adobe Media Encoder when a user opens a malicious 3GP file. The provided description supports sensitive memory disclosure and possible bypass of protections such as ASLR. The title labels it remote code execution, but the supplied details do not explain an execution path. Treat it as high risk for workstations handling untrusted media.
Executive priority
Prioritize remediation on exposed media-handling endpoints. This is not shown as actively exploited, but user-assisted file parsing flaws can enter through normal business workflows and may weaken system defenses.
Technical view
CVE-2021-43757 is a CWE-125 out-of-bounds read in Adobe Media Encoder versions 22.0, 15.4.2 and earlier. Attack complexity is low, no privileges are required, but user interaction is required. The CVSS 3.1 score is 7.8 with high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is most likely on creative, marketing, media, or security-analysis workstations where Adobe Media Encoder is installed and users may open externally supplied 3GP files.
Exploitation context
The bundle does not show known active exploitation, and KEV is false. Exploitation requires convincing a user to open a crafted 3GP file, so phishing, file-sharing, or media-ingest workflows are the realistic paths.
Researcher notes
Evidence is limited to the CVE description and Adobe advisory reference. Do not assume active exploitation or specific fixed versions from this bundle alone. The main confirmed condition is malicious 3GP parsing in affected Adobe Media Encoder versions.
Mitigation direction
- Inventory Adobe Media Encoder installations and versions.
- Check Adobe APSB21-118 for the vendor-approved update or mitigation.
- Prioritize systems processing externally supplied media files.
- Restrict opening untrusted 3GP files until remediated.
- Remove obsolete or unmanaged Media Encoder installations.
Validation and detection
- Confirm whether installed versions are 22.0, 15.4.2, or earlier.
- Verify remediation against Adobe APSB21-118 guidance.
- Review media-ingest workflows for untrusted 3GP handling.
- Check endpoint telemetry for suspicious Media Encoder crashes.
- Document any remaining exceptions and compensating controls.
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-125: 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-2021-43757 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/media-encoder/apsb21-118.htmlCVE reference · vendor-advisory
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.