# CVE-2023-3773: Kernel: xfrm: out-of-bounds read of xfrma_mtimer_thresh nlattr

Status: published. Published: 2023-07-25. Updated: 2026-11-07.

A flaw was found in the Linux kernel’s IP framework for transforming packets (XFRM subsystem). This issue may allow a malicious user with CAP_NET_ADMIN privileges to cause a 4 byte out-of-bounds read of XFRMA_MTIMER_THRESH when parsing netlink attributes, leading to potential leakage of sensitive heap data to userspace.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- Red Hat / Red Hat Enterprise Linux 9 (kernel): ≥ 0:5.14.0-362.8.1.el9_3; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 6 (kernel): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 7 (kernel): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 7 (kernel-rt): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8 (kernel): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8 (kernel-rt): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9 (kernel-rt): Version range not reported. Source: CNA: redhat
- Siemens / SIMATIC S7-1500 TM MFP - GNU/Linux subsystem: ≥ 0; < V1.1 (affected, custom). Source: ADP: siemens-SADP

## Severity and prioritization

- CVSS 3.1: 5.5 (medium); CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N; source: CNA: redhat

- CISA KEV: No listing in collected sources

- EPSS: 0.25% as of 2026-11-07; percentile 16.71%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-125

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://access.redhat.com/errata/RHSA-2023:6583 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/security/cve/CVE-2023-3773 (CNA: redhat; vdb-entry, x_refsource_REDHAT)

- https://bugzilla.redhat.com/show_bug.cgi?id=2218944 (CNA: redhat; issue-tracking, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2023:6583 (ADP: CVE; vendor-advisory, x_refsource_REDHAT, x_transferred)

- https://access.redhat.com/security/cve/CVE-2023-3773 (ADP: CVE; vdb-entry, x_refsource_REDHAT, x_transferred)

- https://bugzilla.redhat.com/show_bug.cgi?id=2218944 (ADP: CVE; issue-tracking, x_refsource_REDHAT, x_transferred)

- https://lists.debian.org/debian-lts-announce/2023/10/msg00027.html (ADP: CVE; x_transferred)

- https://www.debian.org/security/2023/dsa-5492 (ADP: CVE; x_transferred)

- https://cert-portal.siemens.com/productcert/html/ssa-794697.html (ADP: siemens-SADP)

## Provenance

- CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2023-3773; retrieved 2026-11-07; source updated 2026-11-07

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2023-3773; retrieved 2026-11-07; source updated Not reported

Revision: 473c8c47928ee3af4070349e8a41fccf1cf032d5b46132b51d2fc5916e2e9e15

Canonical: https://y2.dev/cve/CVE-2023-3773

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