Security readout for executives and security teams
Plain-English summary
This is a Linux kernel memory leak in the Microchip VCAP API. Under a specific allocation-failure path, memory is not freed correctly. The stated impact is availability, not data theft or privilege escalation. Public sources rate it medium with local, low-privilege access required.
Executive priority
Treat as a normal kernel maintenance item unless exposed systems rely on the affected networking code. It can affect availability, but public evidence does not support emergency response or internet-scale exploitation.
Technical view
The issue is in vcap_dup_rule(). If kzalloc() succeeds and a later kmemdup() fails, duprule, ckf, and caf allocations can leak. The source describes this occurring during CONFIG_VCAP_KUNIT_TEST fault injection. CVSS 3.1 is 5.5: local attack vector, low privileges, high availability impact.
Likely exposure
Exposure is most relevant to Linux kernels in the affected range using the Microchip VCAP API code. Public metadata lists Linux 6.3 through fixed stable updates, but version evidence is sparse. Systems without this kernel code path are less likely to be affected.
Exploitation context
The bundle does not show active exploitation, and KEV status is false. Available evidence describes a memory leak found through KUnit fault injection, not a public exploit. The CVSS vector requires local, low-privilege access and targets availability.
Researcher notes
Focus validation on the vcap_dup_rule() allocation error path and whether the fix frees all partially allocated structures. The affected-version data in the bundle is limited, so distro backport confirmation matters more than raw upstream version comparison.
Mitigation direction
- Upgrade to a kernel or distro release containing the referenced stable fixes.
- Consult Linux distribution advisories for exact backported fixed package versions.
- For custom kernels, apply the referenced upstream stable commits.
- Prioritize systems where Microchip VCAP networking code is enabled or relevant.
Validation and detection
- Inventory running Linux kernel versions against vendor fixed-release guidance.
- Check whether Microchip VCAP API code is built into deployed kernels.
- Confirm patched kernels include one of the referenced stable commits or distro backports.
- Review vulnerability scanner findings for kernel version false positives.
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
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ATT&CK lookup starting points
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CWE-401: Exact CWE lookup
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Open ATT&CK lookupCVE-2023-53303 mapping review
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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/a26ba60413b2c8f95daf0ee0152cf82abd7bfbe4CVE reference, Linux
- https://git.kernel.org/stable/c/281f65d29d6da1a9b6907fb0b145aaf34f4e4822CVE 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.