Security readout for executives and security teams
Plain-English summary
This is a high-severity Android SoC flaw in the PowerVR kernel driver. A local attacker could use a missing bounds check to write outside expected memory and gain higher privileges on the device without user interaction.
Executive priority
Treat as a high-priority mobile endpoint patching issue. It is not described as remotely exploitable, but privilege escalation can materially increase impact after malware, malicious app installation, or physical/local access.
Technical view
CVE-2021-39661 is a CWE-787 out-of-bounds write in _PMRLogicalOffsetToPhysicalOffset in the PowerVR kernel driver. The CVSS 3.1 vector is local, low complexity, low privileges, no user interaction, with high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is limited to Android devices whose SoC/vendor kernel driver stack includes the affected PowerVR component and lacks the relevant Android/OEM security update. The source bundle does not identify specific device models or OEM patch timelines.
Exploitation context
The source describes local privilege escalation requiring no user interaction. It does not support remote exploitation, public weaponization, or active exploitation. The bundled KEV flag is false.
Researcher notes
The public bundle gives the affected product only as Android SoC and references the Android November 2022 bulletin. It does not provide model-level impact, detailed patch mechanics, or exploit evidence, so validation should rely on OEM firmware mapping.
Mitigation direction
- Apply Android/OEM security updates that address CVE-2021-39661.
- Check device vendor advisories for affected models and firmware availability.
- Prioritize managed Android devices with outdated security patch levels.
- Retire or isolate devices that cannot receive vendor fixes.
Validation and detection
- Inventory Android devices and record model, SoC, and security patch level.
- Confirm vendor firmware explicitly includes the CVE-2021-39661 fix.
- Review MDM compliance data for devices missing November 2022-era Android security updates.
- Track unsupported devices separately for replacement or 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-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 lookupCVE-2021-39661 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:L/UI:N/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:L/UI:N/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:L/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://source.android.com/security/bulletin/2022-11-01CVE reference
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.