Security readout for executives and security teams
Plain-English summary
This is a Linux kernel Bluetooth bug that can make the kernel read memory after it has been freed. If triggered, it could affect confidentiality, integrity, and availability. The source rates it high severity, but does not show active exploitation or provide evidence of remote unauthenticated exposure.
Executive priority
Prioritize patching in normal high-severity kernel maintenance cycles, faster for laptops, workstations, and systems using Bluetooth. No source evidence supports emergency KEV-style response, but kernel memory-safety issues can have serious business impact if exposed.
Technical view
CVE-2025-21969 is a CWE-416 use-after-free in Linux Bluetooth L2CAP. The bundle describes a race where hci sync releases l2cap_conn while hci_rx_work later references it in l2cap_send_cmd. The kernel fix adds hci dev locking to synchronize the receive data work queue.
Likely exposure
Most relevant exposure is Linux systems running affected kernel versions with Bluetooth/L2CAP support present. The source data lists Linux as affected and includes stable kernel fix references, but version range formatting is imperfect. Validate against the exact distribution kernel package and vendor advisory.
Exploitation context
The CVSS vector is local, low complexity, low privileges, and no user interaction. The bundle does not identify public exploitation, and KEV is false. Treat exploitation as plausible local privilege-impact risk, not as confirmed active exploitation.
Researcher notes
Evidence comes from the CVE record and kernel stable references. The technical trace shows KASAN detecting slab-use-after-free in l2cap_send_cmd from hci_rx_work. The source does not provide exploit details, proof of exploitation, or distribution-specific package names.
Mitigation direction
- Apply vendor kernel updates that include the referenced stable Linux fixes.
- Prioritize systems where Bluetooth is enabled or required by business workflows.
- If no update is available, review vendor guidance for temporary risk reduction.
- Disable or restrict Bluetooth where operationally feasible until patched.
Validation and detection
- Inventory Linux kernel versions and distribution package build numbers.
- Confirm whether Bluetooth support is enabled on in-scope systems.
- Map deployed kernels to vendor advisories or referenced stable commits.
- Verify patch status through approved endpoint, package, or vulnerability management tooling.
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 lookupCVE-2025-21969 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: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.
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:H/I:H/A:H1.85.9CISA-ADPVulnerability scoring details
Base CVSS 3.1 score
7.8HighVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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/c96cce853542b3b13da3738f35ef1be8cfcc9d1dCVE reference, Linux
- https://git.kernel.org/stable/c/f8094625a591eeb0b75b1bd9e713fac1d93f5ca9CVE reference, Linux
- https://git.kernel.org/stable/c/7790a79c6fce8d5d552bc64f5c82819f719e4f28CVE reference, Linux
- https://git.kernel.org/stable/c/b4f82f9ed43aefa79bec2504ae8c29be0c0f5d1dCVE 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.
Use After Free
Use After Free represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.