قبل بضعة أيام فقط ، اكتشفت مجموعة من العلماء الصينيين ثغرة تسمح بهجمات DDoS مع التضخيم. تمكن المؤلفون من تنفيذ هجوم بمعامل 43000! لا يمكن للهجوم الجديد استنفاد موارد القناة الصادرة لخادم الويب المستهدف فحسب ، ولكن أيضًا قنوات العقد CDN. كانت جميع الفئات الضعيفة 13 من بين 13 أكبر مزودي CDN المثبتين ، بما في ذلك Akamai و Fastly و Cloudflare. تحت القطع ، النظر في آلية الهجوم والتدابير المقترحة من قبل المؤلفين.

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13 CDN : Akamai, Alibaba Cloud, Azure, CDN77, CDNsun, Cloudflare, CloudFront, Fastly, G-Core Labs, Huawei Cloud, KeyCDN, StackPath Tencent Cloud.

- Linux c 2.4GHz CPU, 16G DDR 1000 Mbps .

- Apache/2.4.18 . CDN .

Range request

range request -. . , .

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range CDN - Range. :

1. Laziness () — .
2. Deletion () — .
3. Expansion () — , .

CDN 2 3. , , , , .

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, . 25 MB Akamai 43000!

13 CDN : Akamai, Alibaba Cloud, Azure, CDN77, CDNsun, Cloudflare, CloudFront, Fastly, G-Core Labs, Huawei Cloud, KeyCDN, StackPath Tencent Cloud.

CDN

, . CDN, CDN , Frontend CDN FCDN. CDN, -, Backend CDN (. ).

, :

1. FCDN Laziness Range " ".
2. BCDN , Range .

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CDN RFC.

CDN :

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Source:
CDN Backfired: Amplification Attacks Based on HTTP Range Requests, Weizhong Li, Kaiwen Shen, Run Guo, Baojun Liu, Jia Zhang, Haixin Duan, Shuang Hao, Xiarun Chen, Yao Wan.

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P.S.

CloudFlare , , , .

"They thought that the SBR attack relies on constantly triggering a cache-miss and a customer can add a page rule to ignore query strings. But this does not solve the problem fundamentally. The malicious customers and some normal customers will not follow this suggestion. Unfortunately, they won’t implement our mitigation solutions because Cloudflare does not want to cache partial responses of certain resources."