Security readout for executives and security teams
Plain-English summary
CVE-2025-21739 is a Linux kernel use-after-free in the UFS storage driver cleanup path. A local user could potentially exploit memory corruption with high impact to confidentiality, integrity, and availability. The public source bundle identifies a kernel fix, but does not provide evidence of active exploitation.
Executive priority
Treat as high priority for Linux assets where local users, shared workloads, or UFS driver exposure exist. It is not currently source-supported as internet-exploitable or actively exploited, but kernel memory-safety impact justifies timely patching.
Technical view
The flaw occurs when UFS crypto profile cleanup is registered on the platform device while the underlying ufs_hba allocation can be released earlier through SCSI host deallocation. Later device release can dereference freed crypto_profile memory. The fix changes ufshcd_alloc_host() cleanup ordering using devres-managed SCSI device cleanup.
Likely exposure
Exposure is limited to Linux systems running affected kernel versions and using the UFS core driver paths described in the CVE. The CVSS vector requires local privileges, so remote-only exposure is not indicated by the supplied sources.
Exploitation context
The CVE is not listed as KEV in the supplied bundle, and no cited source states active exploitation. The CVSS vector is local, low complexity, low privileges, no user interaction, with high CIA impact.
Researcher notes
Focus validation on init error and driver removal cleanup ordering around devm_blk_crypto_profile_init(), ufshcd_alloc_host(), ufshcd_dealloc_host(), and SCSI host lifetime. Do not assume exploitability beyond the local CVSS scope without additional evidence.
Mitigation direction
- Apply vendor kernel updates containing the referenced stable fixes.
- Prioritize systems using UFS storage driver functionality.
- Check distribution advisories for exact package versions and reboot requirements.
- If patching is delayed, reduce local user access on exposed systems.
- Monitor kernel and distribution advisories for updated affected-version guidance.
Validation and detection
- Inventory Linux kernel versions across affected fleets.
- Identify systems with UFS driver usage or relevant hardware paths.
- Confirm fixed stable commits or downstream patches are present.
- Review kernel package changelogs for CVE-2025-21739 references.
- Verify patched systems have booted into the updated kernel.
Public sources used
- CVE Program
- CVE List V5
- Linux stable commit 0a6895c03b1f439236e2d22b1a69ebfc1eb9d5ea
- Linux stable commit d06eb2620d3bf16056b8b7ea3744dbb5e30512f4
- Linux stable commit 0dc539b888fb5f56b6eeddd95433eab557d4b0c1
- Linux stable commit 0c77c0d754fe83cb154715fcfec6c3faef94f207
- Linux stable commit 9c185beae09a3eb85f54777edafa227f7e03075d
- Linux stable commit f8fb2403ddebb5eea0033d90d9daae4c88749ada
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-2025-21739 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/0a6895c03b1f439236e2d22b1a69ebfc1eb9d5eaCVE reference, Linux
- https://git.kernel.org/stable/c/d06eb2620d3bf16056b8b7ea3744dbb5e30512f4CVE reference, Linux
- https://git.kernel.org/stable/c/0dc539b888fb5f56b6eeddd95433eab557d4b0c1CVE reference, Linux
- https://git.kernel.org/stable/c/0c77c0d754fe83cb154715fcfec6c3faef94f207CVE reference, Linux
- https://git.kernel.org/stable/c/9c185beae09a3eb85f54777edafa227f7e03075dCVE reference, Linux
- https://git.kernel.org/stable/c/f8fb2403ddebb5eea0033d90d9daae4c88749adaCVE 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.