📄 Description (English)
In the Linux kernel, the following vulnerability has been resolved:
usb: typec: ucsi: validate connector number in ucsi_notify_common()
The connector number extracted from CCI via UCSI_CCI_CONNECTOR() is a
7-bit field (0-127) that is used to index into the connector array in
ucsi_connector_change(). However, the array is only allocated for the
number of connectors reported by the device (typically 2-4 entries).
A malicious or malfunctioning device could report an out-of-range
connector number in the CCI, causing an out-of-bounds array access in
ucsi_connector_change().
Add a bounds check in ucsi_notify_common(), the central point where CCI
is parsed after arriving from hardware, so that bogus connector numbers
are rejected before they propagate further.
🤖 AI Executive Summary
CVE-2026-31729 is a high-severity out-of-bounds array access vulnerability in the Linux kernel's USB Type-C UCSI driver. A malicious or malfunctioning USB device could send a crafted connector number in the CCI field, causing kernel memory corruption and potential denial of service or privilege escalation. The vulnerability affects Linux kernel versions up to 7.0-rc6 and requires a malicious USB device to be connected to the system.
📄 Description (Arabic)
🤖 AI Intelligence Analysis Analyzed: May 7, 2026 20:00
🇸🇦 Saudi Arabia Impact Assessment
This vulnerability primarily impacts Saudi organizations using Linux-based systems with USB Type-C connectivity, particularly: (1) Government agencies and NCA infrastructure running Linux servers with USB device management; (2) Telecommunications sector (STC, Mobily) managing network equipment with USB interfaces; (3) Banking and financial institutions (SAMA-regulated) using Linux infrastructure for payment processing systems; (4) Healthcare organizations running Linux-based medical devices with USB connectivity; (5) Energy sector (ARAMCO, SEC) operating industrial control systems on Linux platforms. The risk is elevated in environments where untrusted USB devices may be connected or where supply chain compromise is a concern.
🏢 Affected Saudi Sectors
Government and Public Administration
Banking and Financial Services
Telecommunications
Healthcare
Energy and Utilities
Defense and Security
🎯 MITRE ATT&CK Techniques
⚖️ Saudi Risk Score (AI)
6.8
/ 10.0
🔧 Remediation Steps (English)
Immediate Actions:
1. Identify all Linux systems running kernel versions prior to 7.0 with USB Type-C UCSI support enabled
2. Restrict physical USB port access to trusted devices only; implement USB port locks or disable unused ports
3. Monitor system logs for kernel panics or memory corruption errors related to USB subsystem
Patching Guidance:
1. Apply the latest stable kernel patch that includes the ucsi_notify_common() bounds check validation
2. For production systems, test patches in staging environment before deployment
3. Prioritize patching for systems in DMZ or with external USB connectivity
4. Update to Linux kernel 7.0 final release or later when available
Compensating Controls (if immediate patching not possible):
1. Disable USB Type-C UCSI driver if not required: echo 'blacklist typec_ucsi' >> /etc/modprobe.d/blacklist.conf
2. Implement kernel module signing and secure boot to prevent unauthorized driver loading
3. Use SELinux or AppArmor policies to restrict USB device access
4. Deploy USB device whitelisting via udev rules
Detection Rules:
1. Monitor kernel logs for: 'ucsi_notify_common' errors or 'connector number out of range' messages
2. Alert on kernel panic messages containing 'usb', 'typec', or 'ucsi'
3. Monitor for unexpected USB device enumeration attempts
4. Track failed USB device initialization events in syslog
🔧 خطوات المعالجة (العربية)
الإجراءات الفورية:
1. تحديد جميع أنظمة Linux التي تعمل بإصدارات نواة سابقة للإصدار 7.0 مع تفعيل دعم UCSI من نوع USB-C
2. تقييد الوصول المادي لمنافذ USB للأجهزة الموثوقة فقط؛ تطبيق أقفال منافذ USB أو تعطيل المنافذ غير المستخدمة
3. مراقبة سجلات النظام للبحث عن أعطال النواة أو أخطاء تلف الذاكرة المتعلقة بنظام USB الفرعي
إرشادات التصحيح:
1. تطبيق أحدث تصحيح نواة مستقر يتضمن التحقق من حدود ucsi_notify_common()
2. بالنسبة للأنظمة الإنتاجية، اختبر التصحيحات في بيئة التجريب قبل النشر
3. أولويات التصحيح للأنظمة في DMZ أو التي تحتوي على اتصالية USB خارجية
4. التحديث إلى إصدار نواة Linux 7.0 النهائي أو أحدث عند توفره
الضوابط البديلة (إذا لم يكن التصحيح الفوري ممكناً):
1. تعطيل برنامج تشغيل UCSI من نوع USB-C إذا لم يكن مطلوباً
2. تطبيق توقيع وحدة النواة والتحقق الآمن لمنع تحميل برنامج التشغيل غير المصرح به
3. استخدام سياسات SELinux أو AppArmor لتقييد الوصول إلى أجهزة USB
4. نشر قائمة بيضاء لأجهزة USB عبر قواعد udev
قواعد الكشف:
1. مراقبة سجلات النواة للبحث عن أخطاء 'ucsi_notify_common' أو رسائل 'رقم الموصل خارج النطاق'
2. التنبيه على رسائل انهيار النواة التي تحتوي على 'usb' أو 'typec' أو 'ucsi'
3. مراقبة محاولات تعداد أجهزة USB غير المتوقعة
4. تتبع أحداث فشل تهيئة جهاز USB في syslog
📋 Regulatory Compliance Mapping
🟢 NCA ECC 2024
ECC 2024 A.12.6.1 - Management of technical vulnerabilities
ECC 2024 A.14.2.1 - Secure development policy
ECC 2024 A.12.2.1 - Monitoring and logging of access to information
🔵 SAMA CSF
SAMA CSF ID.RA-1 - Asset Management and Inventory
SAMA CSF PR.IP-12 - Security patch management
SAMA CSF DE.CM-1 - Detection and monitoring of anomalies
🟡 ISO 27001:2022
ISO 27001:2022 A.12.2.1 - Information and other assets associated with information processing facilities
ISO 27001:2022 A.12.6.1 - Management of technical vulnerabilities
ISO 27001:2022 A.14.2.1 - Secure development policy and procedures
🟣 PCI DSS v4.0.1
PCI DSS 6.2 - Ensure all system components and software are protected from known vulnerabilities
🔗 References & Sources 4
🔗
https://git.kernel.org/stable/c/98429e9ec89a5e3a204112dfaa2dbe6ca28493a0
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Patch
🔗
https://git.kernel.org/stable/c/d2d8c17ac01a1b1f638ea5d340a884ccc5015186
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Patch
🔗
https://git.kernel.org/stable/c/f4e608fe12b7ac6a4a57176ab0296bb5a110a078
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Patch
🔗
https://git.kernel.org/stable/c/f6dcbf2b024d55549959402f1db6c614e51d52cb
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Patch
📦 Affected Products / CPE 9 entries
linux:linux_kernel
linux:linux_kernel
linux:linux_kernel
linux:linux_kernel:7.0
linux:linux_kernel:7.0
linux:linux_kernel:7.0
linux:linux_kernel:7.0
linux:linux_kernel:7.0
linux:linux_kernel:7.0