Security readout for executives and security teams
Plain-English summary
CVE-2025-21770 is a Linux kernel memory leak in IOMMU page-fault handling. When a device is removed from an IOPF queue with pending faults, the kernel can fail to free a related group object. The main business risk is local availability impact from memory exhaustion, not data theft or remote compromise.
Executive priority
Handle through normal kernel patch management, with higher urgency for shared infrastructure where local users or workloads are less trusted. No source indicates active exploitation, but the availability impact justifies timely remediation on critical hosts.
Technical view
The flaw is in iopf_queue_remove_device(). It responds to outstanding IOPFs with IOMMU_PAGE_RESP_INVALID and detaches the device, but did not release the IOPF group afterward. The fix adds iopf_free_group() after the response path. CVSS 3.1 is 5.5: local, low privilege, no user interaction, high availability impact.
Likely exposure
Exposure is likely limited to Linux systems running affected kernel versions and using relevant IOMMU/PRI/IOPF behavior. The provided record does not identify specific distributions or appliances. Vendor backports may change practical exposure, so kernel package provenance matters more than upstream version alone.
Exploitation context
The CVE record shows local attack vector and low privileges required. KEV is false, and the provided sources do not state active exploitation or public exploit availability. Treat this as an availability issue that could matter on multi-user, virtualization, or hardware-intensive systems.
Researcher notes
Evidence supports CWE-401 memory leak in the IOMMU IOPF removal path. The vulnerable condition requires pending IOPFs during device removal from the per-IOMMU queue. The source bundle does not provide distro-specific affected ranges, exploit details, or non-update mitigations.
Mitigation direction
- Update to a kernel containing the referenced stable fixes or your vendor’s backported package.
- Check Linux distribution advisories before relying only on upstream version numbers.
- Prioritize systems where local users or workloads can influence device or IOMMU behavior.
- Monitor affected hosts for abnormal kernel memory growth or availability degradation.
Validation and detection
- Inventory Linux kernel versions and vendor package revisions across exposed systems.
- Compare installed kernels with vendor advisories and the referenced stable commits.
- Identify systems using IOMMU, PRI, or IOPF-capable configurations.
- Review operational telemetry for memory leak symptoms under device removal or PRI-disable events.
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-401: 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-2025-21770 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
- Medium
- CVSS
- 5.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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.
SSVC decision data
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:N/I:N/A:H1.83.6CISA-ADPVulnerability scoring details
Base CVSS 3.1 score
5.5MediumVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://git.kernel.org/stable/c/db60d2d896a17decd58d143eef92cf22eb0a0176CVE reference, Linux
- https://git.kernel.org/stable/c/90d5429cd2921ca2714684ed525898d431bb9283CVE reference, Linux
- https://git.kernel.org/stable/c/9759ae2cee7cd42b95f1c48aa3749bd02b5ddb08CVE reference, Linux
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.
Missing Release of Memory after Effective Lifetime
Missing Release of Memory after Effective Lifetime represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.