Security readout for executives and security teams
Plain-English summary
CVE-2021-39798 is an Android flaw in bitmap parcel handling that could let code already running on a device gain higher local privileges. The public record says Android 12 and 12L are affected, user execution privileges are needed, and no user interaction is required.
Executive priority
Treat this as a high-priority mobile fleet hygiene issue, especially for Android 12/12L devices with enterprise access. Urgency is driven by local privilege escalation impact, not confirmed public exploitation.
Technical view
The issue is in Bitmap_createFromParcel in Bitmap.cpp. A missing bounds check can allow arbitrary code execution and local escalation of privilege from User execution privileges. The source bundle does not provide CVSS, CWE, detailed exploit conditions, or affected OEM build ranges.
Likely exposure
Exposure is most likely on Android 12 or Android 12L devices that have not received OEM updates covering the April 2022 Android Security Bulletin.
Exploitation context
The provided sources do not show known active exploitation or CISA KEV listing. Exploitation is described as local, requiring User execution privileges, with no user interaction needed.
Researcher notes
Public detail is limited to the affected function, missing bounds check, impact, privilege requirement, and affected Android versions. Avoid assuming reachable attack surfaces, exploit reliability, or OEM patch status beyond the cited bulletin.
Mitigation direction
- Inventory Android 12 and 12L devices across managed and unmanaged fleets.
- Apply OEM updates that include the April 2022 Android Security Bulletin or later guidance.
- Prioritize devices handling sensitive business data or privileged enterprise access.
- Check vendor guidance for device-specific availability and patch-level mapping.
- Restrict enterprise access from devices that cannot receive supported security updates.
Validation and detection
- Confirm each device model is Android 12 or 12L, or outside the affected versions.
- Verify Android security patch levels against OEM guidance for the April 2022 bulletin.
- Review MDM compliance data for unsupported or stale Android builds.
- Track exceptions where OEM patch status is unclear or unavailable.
- Reassess exposure when vendors publish device-specific advisories or backport information.
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.
Execution 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-2021-39798 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
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
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 and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://source.android.com/security/bulletin/2022-04-01CVE 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.