Security readout for executives and security teams
Plain-English summary
CVE-2021-29256 is a use-after-free bug in the Arm Mali GPU kernel driver. A low-privileged user could access freed memory and potentially read sensitive data or gain root privileges. Because CISA lists it in KEV, treat affected systems as exposed to real-world exploitation, not only theoretical risk.
Executive priority
Make this a near-term remediation item for any fleet containing affected Mali GPU drivers. The combination of root escalation potential and KEV status raises business urgency, but prioritization should be tied to confirmed device exposure and vendor patch availability.
Technical view
The issue is CWE-416 use-after-free in the Mali GPU kernel driver. It affects Bifrost r16p0-r29p0 before r30p0, Valhall r19p0-r29p0 before r30p0, and Midgard r28p0-r30p0. CVSS 3.1 is 8.8 with high confidentiality, integrity, and availability impact.
Likely exposure
Exposure depends on whether a device vendor shipped an affected Mali kernel driver branch. The supplied record does not enumerate OEM products or operating system builds, so teams need asset and firmware validation rather than assuming all Mali-based devices are affected.
Exploitation context
CISA KEV listing supports that this CVE has been exploited in the wild. The source bundle does not provide exploit mechanics, affected campaigns, or indicators of compromise. Risk is highest where untrusted or low-privileged users can run code on affected devices.
Researcher notes
The public bundle confirms affected Mali driver version ranges, CWE-416, CVSS 8.8, and KEV status. It does not identify OEM models, exploit details, or universal remediation steps. Validation should focus on kernel driver provenance, downstream vendor patch mapping, and whether fixed firmware is installed.
Mitigation direction
- Check Arm and device vendor advisories for fixed Mali GPU kernel driver guidance.
- Prioritize driver or firmware updates moving affected branches to non-vulnerable vendor releases.
- Reduce exposure from untrusted local users or applications on affected devices.
- Track CISA KEV remediation expectations for covered environments.
- If no vendor fix is available, document compensating controls and vendor support status.
Validation and detection
- Inventory devices using Arm Mali GPU kernel drivers.
- Identify driver branch and revision: Bifrost, Valhall, or Midgard.
- Compare installed versions with the affected ranges in the CVE record.
- Confirm whether OEM firmware includes Arm's corrected driver line.
- Review vulnerability management tools for CVE-2021-29256 detections and false negatives.
- Check CISA KEV status when setting remediation priority.
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-416: 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 lookupPrivilege behavior lookup
The CVE wording references privilege impact, so privilege escalation and authorization behavior review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-29256 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
- 8.8 (3.1)
- Known Exploited
- Yes
- Published
Vector: CVSS:3.1/AV:N/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.
CISA KEV status
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:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H2.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.8HighVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://developer.arm.com/support/arm-security-updates/mali-gpu-kernel-driverCVE reference · x_refsource_CONFIRM
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-29256CVE reference · government-resource
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.
Use After Free
Use After Free represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.