📄 Description (English)
cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to version 0.30.0, the ``write_headers`` function does not check for CR & LF characters in user supplied headers, allowing untrusted header value to escape header lines.
This vulnerability allows attackers to add extra headers, modify request body unexpectedly & trigger an SSRF attack. When combined with a server that supports http1.1 pipelining (springboot, python twisted etc), this can be used for server side request forgery (SSRF). Version 0.30.0 fixes this issue.
🤖 AI Executive Summary
CVE-2026-21428 is a header injection vulnerability in cpp-httplib versions prior to 0.30.0 that allows attackers to inject CR/LF characters into HTTP headers, enabling header manipulation, request body modification, and SSRF attacks. With an exploit already available and affecting widely-used HTTP libraries in enterprise applications, this poses an immediate risk to Saudi organizations using vulnerable versions. The vulnerability is particularly dangerous when combined with HTTP/1.1 pipelining-enabled servers, making it critical for rapid patching.
📄 Description (Arabic)
🤖 AI Intelligence Analysis Analyzed: May 3, 2026 17:09
🇸🇦 Saudi Arabia Impact Assessment
This vulnerability poses significant risk to Saudi financial institutions (SAMA-regulated banks), government agencies (NCA oversight), and telecommunications providers (STC, Mobily) that utilize cpp-httplib in their API gateways, microservices, or internal HTTP clients. Energy sector organizations (ARAMCO, SEC) using this library in SCADA or operational technology systems face SSRF risks that could lead to lateral movement and critical infrastructure compromise. Healthcare providers and e-commerce platforms are also at risk for data exfiltration and unauthorized access through header injection attacks.
🏢 Affected Saudi Sectors
Banking and Financial Services
Government and Public Administration
Telecommunications
Energy and Utilities
Healthcare
E-commerce and Retail
Technology and Software Development
🎯 MITRE ATT&CK Techniques
⚖️ Saudi Risk Score (AI)
8.2
/ 10.0
🔧 Remediation Steps (English)
IMMEDIATE ACTIONS:
1. Identify all applications and services using cpp-httplib library versions prior to 0.30.0 through dependency scanning and software inventory tools
2. Isolate or restrict network access to affected services until patching is completed
3. Enable HTTP request logging and monitoring for suspicious header patterns (CR/LF sequences, duplicate headers)
PATCHING GUIDANCE:
1. Upgrade cpp-httplib to version 0.30.0 or later immediately
2. Recompile all dependent applications with the patched library version
3. Conduct regression testing before production deployment
4. Prioritize patching for internet-facing services and API gateways
COMPENSATING CONTROLS (if immediate patching not possible):
1. Implement WAF rules to detect and block CR/LF injection attempts in HTTP headers
2. Deploy reverse proxy (nginx, Apache) with header validation and sanitization
3. Disable HTTP/1.1 pipelining on backend servers if operationally feasible
4. Implement strict input validation at application layer for all user-supplied header values
DETECTION RULES:
1. Monitor for HTTP requests containing %0D%0A (URL-encoded CR/LF) in header values
2. Alert on duplicate or malformed headers in request logs
3. Track SSRF indicators: requests to internal IP ranges (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16, 127.0.0.1)
4. Implement YARA rule: detect CR/LF sequences (0x0D0A) in HTTP header parsing
🔧 خطوات المعالجة (العربية)
الإجراءات الفورية:
1. تحديد جميع التطبيقات والخدمات التي تستخدم مكتبة cpp-httplib الإصدارات السابقة للإصدار 0.30.0 من خلال أدوات فحص التبعيات
2. عزل أو تقييد الوصول إلى الشبكة للخدمات المتأثرة حتى اكتمال التصحيح
3. تفعيل تسجيل مراقبة طلبات HTTP للأنماط المريبة (تسلسلات CR/LF، رؤوس مكررة)
إرشادات التصحيح:
1. ترقية cpp-httplib إلى الإصدار 0.30.0 أو أحدث فوراً
2. إعادة تجميع جميع التطبيقات التابعة باستخدام إصدار المكتبة المصحح
3. إجراء اختبار الانحدار قبل نشر الإنتاج
4. إعطاء الأولوية لتصحيح الخدمات المواجهة للإنترنت وبوابات API
الضوابط البديلة (إذا لم يكن التصحيح الفوري ممكناً):
1. تنفيذ قواعد WAF للكشف عن محاولات حقن CR/LF وحجبها في رؤوس HTTP
2. نشر وكيل عكسي (nginx، Apache) مع التحقق من الرؤوس والتطهير
3. تعطيل HTTP/1.1 pipelining على خوادم الواجهة الخلفية إن أمكن
4. تنفيذ التحقق الصارم من المدخلات على مستوى التطبيق لجميع قيم الرؤوس المزودة من قبل المستخدم
قواعد الكشف:
1. مراقبة طلبات HTTP التي تحتوي على %0D%0A (CR/LF المشفرة بـ URL) في قيم الرؤوس
2. التنبيه على الرؤوس المكررة أو المشوهة في سجلات الطلب
3. تتبع مؤشرات SSRF: الطلبات إلى نطاقات IP الداخلية
4. تنفيذ قاعدة YARA: الكشف عن تسلسلات CR/LF في معالجة رؤوس HTTP
📋 Regulatory Compliance Mapping
🟢 NCA ECC 2024
ECC 2024 A.14.2.1 - Information security requirements for supplier relationships
ECC 2024 A.14.2.5 - Addressing information security in supplier agreements
ECC 2024 A.12.6.1 - Management of technical vulnerabilities
🔵 SAMA CSF
SAMA CSF ID.BE-3.1 - Organizational resilience objectives
SAMA CSF PR.DS-6 - Data is protected from unauthorized access
SAMA CSF DE.CM-1 - The network is monitored to detect potential cybersecurity events
🟡 ISO 27001:2022
ISO 27001:2022 A.8.1 - Organizational controls for information security
ISO 27001:2022 A.12.6.1 - Management of technical vulnerabilities
ISO 27001:2022 A.14.2.1 - Supplier relationship information security requirements
🟣 PCI DSS v4.0.1
PCI DSS 6.2 - Ensure all system components and software are protected from known vulnerabilities
PCI DSS 11.2 - Run automated vulnerability scanning tools regularly
🔗 References & Sources 3
🔗
https://github.com/yhirose/cpp-httplib/commit/98048a033a532ff22320ce1d11789f8d5710dfcd
security-advisories@github.com
Patch
🔗
https://github.com/yhirose/cpp-httplib/releases/tag/v0.30.0
security-advisories@github.com
Product
Release Notes
🔗
https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-wpc6-j37r-jcx7
security-advisories@github.com
Exploit
Third Party Advisory
📦 Affected Products / CPE 1 entries
yhirose:cpp-httplib