Security readout for executives and security teams
Plain-English summary
CVE-2025-21649 is a Linux kernel crash bug in the hns3 network driver on HIP08 devices. A local user able to send affected timestamped network traffic can trigger a NULL pointer dereference, causing denial of service. The source does not show data theft, privilege escalation, or active exploitation.
Executive priority
Treat as a targeted availability risk, not a broad internet-facing compromise. Patch affected Linux hosts during normal security maintenance, with higher urgency for production systems where local users or workloads could cause service interruption.
Technical view
HIP08 hns3 devices do not register PTP devices, leaving hdev->ptp NULL. The transmit path can still process SKBTX_HW_TSTAMP and call hclge_ptp_set_tx_info, dereferencing NULL and crashing the kernel. CVSS 3.1 is 5.5 with local attack vector, low complexity, low privileges, and high availability impact.
Likely exposure
Exposure is most likely on Linux systems using Huawei hns3/HIP08 network hardware with affected kernel builds before the referenced stable fixes or distribution backports. Generic Linux systems without this driver, hardware, or code path are less likely exposed.
Exploitation context
The CVE is not listed as KEV, and the provided sources do not claim active exploitation. The described trigger is local and availability-focused: a crash during transmission handling when the hns3 driver processes hardware timestamping state without a registered PTP device.
Researcher notes
Evidence supports CWE-476 and a local denial-of-service condition in the hns3 transmit timestamp path. The affected-version data in the bundle is sparse and commit-oriented, so confirm exposure through kernel package metadata, driver presence, hardware inventory, and downstream vendor advisories.
Mitigation direction
- Update to a kernel containing the referenced stable fixes or vendor backport.
- Check Linux distribution advisories for exact fixed package versions.
- Prioritize affected HIP08 hns3 hosts that support multi-tenant or untrusted local workloads.
- If patching is delayed, follow vendor guidance for compensating controls.
Validation and detection
- Inventory systems using hns3 driver and HIP08 network devices.
- Map running kernel versions to distribution backports or the referenced stable commits.
- Review kernel logs for hclge_ptp_set_tx_info or hns3_nic_net_xmit NULL dereference crashes.
- Confirm patched source or packages guard the missing PTP device path.
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-476: 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-2025-21649 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/f19ab3ef96d9626e5f1bdc56d3574c355e83d623CVE reference, Linux
- https://git.kernel.org/stable/c/9741e72b2286de8b38de9db685588ac421a95c87CVE 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.
NULL Pointer Dereference
NULL Pointer Dereference represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.