📄 Description (English)
A flaw was found in Keycloak. An authenticated user with low privileges can exploit this vulnerability by sending an oversized subject_token JSON Web Token (JWT) to the TokenEndpoint. When the token exceeds a 4000-character limit, it is silently dropped, causing the system to fall back to client credentials. This allows the user to gain the permissions of the client's service account, leading to privilege escalation.
🤖 AI Executive Summary
A privilege escalation vulnerability in Keycloak allows authenticated users with low privileges to exploit token size limits by sending oversized JWT tokens (>4000 characters) to the TokenEndpoint. When the oversized token is silently dropped, the system falls back to client credentials, granting attackers the permissions of the client's service account. This medium-severity flaw (CVSS 6.8) poses significant risk to organizations using Keycloak for identity and access management, particularly in critical sectors managing sensitive data and services.
📄 Description (Arabic)
🤖 AI Intelligence Analysis Analyzed: May 30, 2026 08:25
🇸🇦 Saudi Arabia Impact Assessment
Saudi organizations using Keycloak for identity management face significant risk, particularly: (1) Banking sector and SAMA-regulated institutions relying on Keycloak for customer and employee authentication; (2) Government agencies (NCA, NCSC) using Keycloak for secure access to critical systems; (3) Healthcare providers managing patient data access; (4) Energy sector (ARAMCO, utilities) protecting operational technology access; (5) Telecommunications (STC, Mobily) managing subscriber authentication. The privilege escalation could allow attackers to access sensitive financial data, government systems, patient records, and critical infrastructure controls. Organizations with multi-tenant Keycloak deployments face elevated risk of lateral movement and data breach.
🏢 Affected Saudi Sectors
Banking and Financial Services
Government and Public Administration
Healthcare and Medical Services
Energy and Utilities
Telecommunications
Critical Infrastructure
Education and Research
E-commerce and Retail
🎯 MITRE ATT&CK Techniques
T1078 - Valid Accounts (exploitation of authenticated user access)
T1548 - Abuse Elevation Control Mechanism (privilege escalation via token manipulation)
T1556 - Modify Authentication Process (exploitation of authentication fallback mechanism)
T1110 - Brute Force (potential for automated token size testing)
T1087 - Account Discovery (identifying service accounts with elevated privileges)
T1098 - Account Manipulation (leveraging escalated privileges)
T1040 - Network Sniffing (potential interception of oversized tokens)
⚖️ Saudi Risk Score (AI)
7.2
/ 10.0
🔧 Remediation Steps (English)
IMMEDIATE ACTIONS:
1. Audit all Keycloak instances for oversized JWT token submissions in TokenEndpoint logs (search for tokens >4000 characters or token processing failures)
2. Review service account permissions and identify which accounts have excessive privileges
3. Implement network-level monitoring for suspicious token patterns
4. Disable or restrict low-privilege user access to TokenEndpoint if not required
COMPENSATING CONTROLS (until patch available):
1. Implement strict JWT token size validation at API gateway/WAF level (reject tokens >4000 characters with error response, not silent drop)
2. Configure Keycloak to log all token processing failures and oversized token attempts
3. Implement rate limiting on TokenEndpoint to detect automated exploitation attempts
4. Enable multi-factor authentication for all service account access
5. Restrict service account credentials to minimal required permissions (principle of least privilege)
6. Implement IP whitelisting for TokenEndpoint access
7. Deploy behavioral analytics to detect unusual privilege escalation patterns
DETECTION RULES:
1. Alert on TokenEndpoint requests with JWT tokens exceeding 3800 characters
2. Alert on successful authentication following failed token processing
3. Alert on service account permission usage by non-service account principals
4. Monitor for repeated oversized token submissions from same user/IP
5. Track fallback to client credentials authentication patterns
PATCHING:
1. Monitor Keycloak security advisories for patch release
2. Prepare test environment for patch validation
3. Plan maintenance window for production deployment
4. Verify patch effectiveness by testing oversized token rejection
🔧 خطوات المعالجة (العربية)
الإجراءات الفورية:
1. تدقيق جميع مثيلات Keycloak للتحقق من إرسال رموز JWT كبيرة الحجم في سجلات TokenEndpoint (البحث عن رموز >4000 حرف أو فشل معالجة الرموز)
2. مراجعة صلاحيات حساب الخدمة وتحديد الحسابات التي لديها امتيازات مفرطة
3. تنفيذ المراقبة على مستوى الشبكة للأنماط المريبة للرموز
4. تعطيل أو تقييد وصول المستخدمين ذوي الامتيازات المنخفضة إلى TokenEndpoint إذا لم يكن مطلوباً
الضوابط التعويضية (حتى توفر التصحيح):
1. تنفيذ التحقق الصارم من حجم رمز JWT على مستوى بوابة API/WAF (رفض الرموز >4000 حرف برسالة خطأ، وليس حذف صامت)
2. تكوين Keycloak لتسجيل جميع فشل معالجة الرموز ومحاولات الرموز الكبيرة
3. تنفيذ تحديد معدل على TokenEndpoint للكشف عن محاولات الاستغلال الآلي
4. تفعيل المصادقة متعددة العوامل لجميع وصول حساب الخدمة
5. تقييد بيانات اعتماد حساب الخدمة للصلاحيات المطلوبة الحد الأدنى
6. تنفيذ القائمة البيضاء للعناوين IP لوصول TokenEndpoint
7. نشر تحليلات السلوك للكشف عن أنماط تصعيد الامتيازات غير العادية
قواعد الكشف:
1. تنبيه على طلبات TokenEndpoint برموز JWT تتجاوز 3800 حرف
2. تنبيه على المصادقة الناجحة بعد فشل معالجة الرموز
3. تنبيه على استخدام صلاحيات حساب الخدمة من قبل مبادئ غير حساب الخدمة
4. مراقبة محاولات الرموز الكبيرة المتكررة من نفس المستخدم/IP
5. تتبع أنماط المصادقة الاحتياطية لبيانات اعتماد العميل
التصحيح:
1. مراقبة تنبيهات أمان Keycloak لإصدار التصحيح
2. تحضير بيئة الاختبار للتحقق من صحة التصحيح
3. تخطيط نافذة الصيانة لنشر الإنتاج
4. التحقق من فعالية التصحيح بواسطة اختبار رفض الرموز الكبيرة
📋 Regulatory Compliance Mapping
🟢 NCA ECC 2024
ECC 2024 A.5.1.1 - Access Control Policy (privilege escalation prevention)
ECC 2024 A.5.2.1 - User Registration and Access Rights Management
ECC 2024 A.5.3.1 - Password Management (authentication mechanism security)
ECC 2024 A.8.2.1 - User Access Logging and Monitoring
ECC 2024 A.12.4.1 - Event Logging (detection of privilege escalation attempts)
🔵 SAMA CSF
SAMA CSF ID.AM-2 - Software, hardware, and firmware inventory and ownership
SAMA CSF PR.AC-1 - Identities and credentials are issued, managed, verified, revoked, and audited
SAMA CSF PR.AC-3 - Access is managed based on the principle of least privilege
SAMA CSF DE.CM-1 - The network is monitored to detect potential cybersecurity events
SAMA CSF DE.AE-1 - A baseline of network operations and expected data flows is established
🟡 ISO 27001:2022
ISO 27001:2022 A.5.2 - User access provisioning and de-provisioning
ISO 27001:2022 A.5.3 - Management of privileged access rights
ISO 27001:2022 A.8.2 - User access management
ISO 27001:2022 A.8.3 - Management of supplier access
ISO 27001:2022 A.8.4 - Access rights review
ISO 27001:2022 A.12.4 - Logging of user access and security events
🟣 PCI DSS v4.0.1
PCI DSS 2.1 - Establish configuration standards for system components
PCI DSS 6.2 - Ensure security patches are installed within one month
PCI DSS 7.1 - Implement least privilege access
PCI DSS 8.2 - Assign unique user IDs
PCI DSS 10.2 - Implement automated audit trails for access to cardholder data