Security readout for executives and security teams
Plain-English summary
CVE-2025-21783 is a Linux kernel availability issue. Under a specific GPIO library error path, the kernel can hit a NULL pointer dereference and crash. The public scoring indicates local access with low privileges is required. There is no source-provided evidence of active exploitation.
Executive priority
Treat as a routine but real availability risk. It is not described as remotely exploitable, and no active exploitation is cited. Prioritize patching shared, multi-user, or production Linux systems where a local crash could affect business services.
Technical view
The bug is in gpiolib gpiochip_get_ngpios(). It used chip_* logging macros before gpiodev was initialized, including when reached via bgpio_init(). On error handling, those macros can dereference NULL. The fix replaces chip_* logging with dev_* logging. CVSS 3.1 is 5.5: local, low complexity, low privileges, no user interaction, availability impact only.
Likely exposure
Linux systems running affected kernel builds that include the vulnerable gpiolib code path may be exposed, especially where GPIO-related drivers or initialization paths are relevant. Exposure depends on the exact kernel branch, vendor backports, configuration, and hardware use.
Exploitation context
The CVSS vector indicates exploitation requires local low-privileged access and does not require user interaction. The known impact is denial of service through a kernel crash. The source bundle does not show CISA KEV listing or other evidence of active exploitation.
Researcher notes
Evidence is limited to the CVE record and Linux stable commits. The issue is CWE-476 NULL pointer dereference in a gpiolib error-printing path. Avoid assuming exploitability beyond local denial of service unless additional vendor or researcher evidence becomes available.
Mitigation direction
- Update to a vendor kernel containing the referenced stable fix.
- If self-maintaining kernels, review and apply the relevant upstream stable commit.
- Prioritize systems where local users or workloads can access affected kernel paths.
- Check distribution advisories for backported fixes and reboot requirements.
Validation and detection
- Inventory Linux kernel versions and vendor package release levels.
- Compare running kernels against vendor advisories for CVE-2025-21783.
- Confirm whether referenced stable fixes are present in source or package changelogs.
- Verify systems rebooted into the corrected kernel after update.
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-2025-21783 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/4d9b2b62e1136d10f661ec4c0c268140b6f74f4fCVE reference, Linux
- https://git.kernel.org/stable/c/a7052afa9eae2239e25943baa8817a6a56e8aa68CVE reference, Linux
- https://git.kernel.org/stable/c/189fb76215e479c10731baabb50f1a352d2078f5CVE reference, Linux
- https://git.kernel.org/stable/c/7b4aebeecbbd5b5fe73e35fad3f62ed21aa7ef44CVE 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.