LiveActive security incident?Get immediate response
CVE Record

CVE-2023-53516: macvlan: add forgotten nla_policy for IFLA_MACVLAN_BC_CUTOFF

In the Linux kernel, the following vulnerability has been resolved: macvlan: add forgotten nla_policy for IFLA_MACVLAN_BC_CUTOFF The previous commit 954d1fa1ac93 ("macvlan: Add netlink attribute for broadcast cutoff") added one additional attribute named IFLA_MACVLAN_BC_CUTOFF to allow broadcast cutfoff. However, it forgot to describe the nla_policy at macvlan_policy (drivers/net/macvlan.c). Hence, this suppose NLA_S32 (4 bytes) integer can be faked as empty (0 bytes) by a malicious user, which could leads to OOB in heap just like CVE-2023-3773. To fix it, this commit just completes the nla_policy description for IFLA_MACVLAN_BC_CUTOFF. This enforces the length check and avoids the potential OOB read.

UnknownCVSS not scoredNot KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2023-53516 is a Linux kernel macvlan bug where a missing input-length rule could let a malicious user send a malformed network configuration attribute and trigger a heap out-of-bounds read. The public sources identify a kernel fix, but do not provide a CVSS score or exploitation evidence.

Executive priority

Treat this as a kernel hardening update with potentially local operational impact, not as an internet-facing emergency based on current evidence. Patch through normal kernel maintenance, faster on shared, multi-tenant, or container-heavy Linux hosts.

Technical view

The macvlan code added IFLA_MACVLAN_BC_CUTOFF but omitted its nla_policy entry in drivers/net/macvlan.c. A value expected to be NLA_S32, four bytes, could be represented as zero bytes, creating a potential heap out-of-bounds read. The stable fixes add the missing policy to enforce length validation.

Likely exposure

Exposure is most relevant to Linux systems running the listed affected 6.4 or 6.5 kernel ranges with macvlan functionality present. The source does not specify required privileges, reachable interfaces, or whether containerized environments change practical exposure.

Exploitation context

The CVE is not listed as CISA KEV in the supplied bundle, and no provided source states active exploitation. The description says a malicious user could fake an empty netlink attribute, but evidence of public weaponization is not included.

Researcher notes

Key uncertainty is exploitability context: the sources identify a malformed netlink attribute and potential heap OOB read, but do not state privilege requirements, information disclosure impact, crash behavior, CVSS, or exploit availability. Avoid assuming more than the kernel fix description supports.

Mitigation direction

  • Update to a Linux kernel containing the referenced stable fixes.
  • Prioritize hosts that use macvlan or untrusted local/container workloads.
  • Check Linux distribution advisories for backported kernel fixes.
  • If patching is delayed, review vendor guidance for macvlan exposure reduction.

Validation and detection

  • Inventory Linux kernel versions against the affected 6.4 and 6.5 ranges.
  • Confirm whether the stable fix commits are present or backported.
  • Identify systems where macvlan is configured or available.
  • Review vendor kernel changelogs for CVE-2023-53516 coverage.
Prepared
Confidence
medium
Sources
4

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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.

cve · low confidence lookup

CVE-2023-53516 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

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.

0CVSS vectors
3Timeline events
0ADP providers
3Source links

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux954d1fa1ac93aa8a66f7d9a9ba545cf7f020d348, 954d1fa1ac93aa8a66f7d9a9ba545cf7f020d348unaffected
LinuxLinux6.4, 0, 6.4.8, 6.5affected
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.