Buffer overflow in Linux

CVE-2023-53516

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.

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.001 (3.0th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 3rd percentile — 3.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2023-53516: held from 0.001 to 0.001.

EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: 0.000

Affected products

  • Linux — versions 954d1fa1ac93aa8a66f7d9a9ba545cf7f020d348, 6.4, 0
  • Linux Kernel — versions 6.5

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2023-53516?
CVE-2023-53516 is a high-severity vulnerability in Linux, classified under Out-of-bounds Write. CVSS score: 7.8/10. Published 2025-10-01.
How severe is CVE-2023-53516?
High severity. CVSS v3 base score is 7.8 out of 10.