CVE-2023-39192

Kernel: netfilter: xtables out-of-bounds read in u32_match_it()

MEDIUM
6
CVSS Score
Published: October 9, 2023 at 05:57 PM UTC
Updated: October 15, 2026 at 12:16 AM UTC
3 products affected across 3 vendorsLinux KernelFedoraEnterprise Linux

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Severity
MEDIUM6
Exploit prediction
EPSS 0.4%
SSVC
No known exploit

Description

A flaw was found in the Netfilter subsystem in the Linux kernel. The xt_u32 module did not validate the fields in the xt_u32 structure. This flaw allows a local privileged attacker to trigger an out-of-bounds read by setting the size fields with a value beyond the array boundaries, leading to a crash or information disclosure.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 6.6
Affected range stops below 6.6, so it looks safe — our inference, not a vendor statement
Vendor states this is fixed in 0:4.18.0-553.el8_10 (unaffected)
Vendor states this is fixed in 0:4.18.0-553.rt7.342.el8_10 (unaffected)
Vendor states this is fixed in 9 (unaffected)
Vendor states this is fixed in 6 (unknown)
Vendor states this is fixed in 7 (unknown)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (9)

VDB Entryx_refsource_REDHATThird Party Advisory
https://access.redhat.com/security/cve/CVE-2023-39192
Issue Trackingx_refsource_REDHATPatchThird Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2226784
Source: af854a3a-2127-422b-91ae-364da2661108
https://lists.debian.org/debian-lts-announce/2024/01/msg00004.html
Source: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
https://cert-portal.siemens.com/productcert/html/ssa-398330.html
Source: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
https://cert-portal.siemens.com/productcert/html/ssa-769027.html

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
HIGH
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-125

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