Security readout for executives and security teams
CVE-2021-3490 is a Linux kernel flaw in eBPF verification. A low-privileged local user could potentially turn incorrect bounds tracking into kernel memory reads/writes and arbitrary code execution. The business concern is privilege escalation on affected Linux hosts, not remote internet scanning. Exposure is most likely on Linux systems running affected 5.7 through 5.12-era kernels or vendor kernels carrying the vulnerable backports. Risk is higher where low-privileged local users, workloads, or tenants can reach eBPF functionality. Vendor package status matters more than upstream version strings alone. Prioritize patching on shared Linux infrastructure, developer systems, and any host where local users or workloads are not fully trusted. This is not presented as remotely exploitable, but successful abuse could give kernel-level control after local access. Mitigation focus: Update to vendor kernels containing the upstream fix or stable backports.; Use Linux 5.12.4, 5.11.21, 5.10.37, or later fixed vendor equivalents.; Review Ubuntu USN-4949-1 and USN-4950-1 if Ubuntu kernels are in scope..
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
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ATT&CK lookup starting points
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CWE-20: Exact CWE lookup
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Open ATT&CK lookupCWE-787: Exact CWE lookup
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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-2021-3490 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:H/PR:L/UI:N/S:C/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:H/PR:L/UI:N/S:C/C:H/I:H/A:H1.16Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.8HighVector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://ubuntu.com/security/notices/USN-4950-1CVE reference · vendor-advisory, x_refsource_UBUNTU
- https://ubuntu.com/security/notices/USN-4949-1CVE reference · vendor-advisory, x_refsource_UBUNTU
- [oss-security] CVE-2021-3490 - Linux kernel eBPF bitwise ops ALU32 bounds trackingCVE reference · mailing-list, x_refsource_MLIST
- https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git/commit/?id=049c4e13714ecbca567b4d5f6d563f05d431c80eCVE reference · x_refsource_MISC
- https://www.zerodayinitiative.com/advisories/ZDI-21-606/CVE reference · x_refsource_MISC
- https://security.netapp.com/advisory/ntap-20210716-0004/CVE reference · x_refsource_CONFIRM
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.
Improper Input Validation
Improper Input Validation represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
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.