CVE-2023-39193

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

publishedCWE-125

A flaw was found in the Netfilter subsystem in the Linux kernel. The sctp_mt_check did not validate the flag_count field. This flaw allows a local privileged (CAP_NET_ADMIN) attacker to trigger an out-of-bounds read, leading to a crash or information disclosure.

Technical severity6.1 mediumCVSS 3.1 · CNA: redhat

Published2023-10-09Source updated 2026-11-07

Collected2026-11-072 attributed sources

Fixes and workarounds

Workaround

This flaw can be mitigated by preventing the affected `xt_sctp` kernel module from being loaded. For instructions on how to blacklist a kernel module, please see https://access.redhat.com/solutions/41278.

Source: CNA: redhat

Affected products and versions

Affected products, source version ranges and reporting authorities
Product	Versions	Authority
Red Hat Enterprise Linux 8 Red Hat `kernel-rt` https://access.redhat.com/downloads/content/package-browser/	≥ 0:4.18.0-553.rt7.342.el8_10; < * (unaffected, rpm) Other versions: affected	CNA: redhat
Red Hat Enterprise Linux 8 Red Hat `kernel` https://access.redhat.com/downloads/content/package-browser/	≥ 0:4.18.0-553.el8_10; < * (unaffected, rpm) Other versions: affected	CNA: redhat
Red Hat Enterprise Linux 9 Red Hat `kernel` https://access.redhat.com/downloads/content/package-browser/	≥ 0:5.14.0-427.13.1.el9_4; < * (unaffected, rpm) Other versions: affected	CNA: redhat
Red Hat Enterprise Linux 6 Red Hat `kernel` https://access.redhat.com/downloads/content/package-browser/	Range not reported Other versions: unknown	CNA: redhat
Red Hat Enterprise Linux 7 Red Hat `kernel` https://access.redhat.com/downloads/content/package-browser/	Range not reported Other versions: unknown	CNA: redhat
Red Hat Enterprise Linux 7 Red Hat `kernel-rt` https://access.redhat.com/downloads/content/package-browser/	Range not reported Other versions: unknown	CNA: redhat
Red Hat Enterprise Linux 9 Red Hat `kernel-rt` https://access.redhat.com/downloads/content/package-browser/	Range not reported Other versions: affected	CNA: redhat
SIMATIC S7-1500 CPU 1518-4 PN/DP MFP Siemens	≥ V3.1.0; < V3.1.5 (affected, custom) Other versions: unknown	ADP: siemens-SADP
SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP Siemens	≥ V3.1.0; < V3.1.5 (affected, custom) Other versions: unknown	ADP: siemens-SADP
SIMATIC S7-1500 TM MFP - GNU/Linux subsystem Siemens	≥ 0; < V1.1 (affected, custom) Other versions: unknown	ADP: siemens-SADP
SIPLUS S7-1500 CPU 1518-4 PN/DP MFP Siemens	≥ V3.1.0; < V3.1.5 (affected, custom) Other versions: unknown	ADP: siemens-SADP

Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.

CVSS assessments

CVSS scores, vectors and reporting authorities
Version / score	Vector	Authority
3.1 / 6.1 medium	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:L`	CNA: redhat

Exploit evidence

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

References

https://access.redhat.com/errata/RHSA-2024:2394CNA: redhat · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2024:2950CNA: redhat · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2024:3138CNA: redhat · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/security/cve/CVE-2023-39193CNA: redhat · vdb-entry, x_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2226787CNA: redhat · issue-tracking, x_refsource_REDHAT
https://www.zerodayinitiative.com/advisories/ZDI-CAN-18866/CNA: redhat
https://access.redhat.com/errata/RHSA-2024:2394ADP: CVE · vendor-advisory, x_refsource_REDHAT, x_transferred
https://access.redhat.com/errata/RHSA-2024:2950ADP: CVE · vendor-advisory, x_refsource_REDHAT, x_transferred
https://access.redhat.com/errata/RHSA-2024:3138ADP: CVE · vendor-advisory, x_refsource_REDHAT, x_transferred
https://access.redhat.com/security/cve/CVE-2023-39193ADP: CVE · vdb-entry, x_refsource_REDHAT, x_transferred
https://bugzilla.redhat.com/show_bug.cgi?id=2226787ADP: CVE · issue-tracking, x_refsource_REDHAT, x_transferred
https://lists.debian.org/debian-lts-announce/2024/01/msg00004.htmlADP: CVE · x_transferred
https://www.zerodayinitiative.com/advisories/ZDI-CAN-18866/ADP: CVE · x_transferred
https://cert-portal.siemens.com/productcert/html/ssa-794697.htmlADP: siemens-SADP
https://cert-portal.siemens.com/productcert/html/ssa-398330.htmlADP: siemens-SADP
https://cert-portal.siemens.com/productcert/html/ssa-769027.htmlADP: siemens-SADP

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