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HTTP/2 'MadeYouReset' Vulnerability Enables Large-Scale DoS Attacks

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A new HTTP/2 vulnerability named MadeYouReset allows attackers to bypass server-imposed limits on concurrent requests, enabling large-scale denial-of-service (DoS) attacks. The flaw affects multiple products, including Apache Tomcat, F5 BIG-IP, and Netty. The vulnerability exploits the RST_STREAM frame to create a denial-of-service condition, potentially leading to out-of-memory crashes in some implementations. The MadeYouReset vulnerability leverages the RST_STREAM frame to trigger protocol violations, prompting the server to reset the stream. This bypasses existing mitigations for similar attacks like Rapid Reset and CONTINUATION Flood. The issue has been assigned the CVE identifier CVE-2025-8671, with specific CVEs for affected products. Multiple vendors have acknowledged the vulnerability and are working on patches. Researchers from Tel Aviv University identified the MadeYouReset vulnerability and disclosed it to over 100 vendors. The vulnerability can potentially affect up to one-third of all websites globally. Some vendors were already protected due to changes made after the Rapid Reset vulnerability, while others have implemented patches more recently.

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  1. 14.08.2025 18:20 2 articles · 1mo ago

    HTTP/2 'MadeYouReset' Vulnerability Enables Large-Scale DoS Attacks

    Researchers from Tel Aviv University identified the MadeYouReset vulnerability and disclosed it to over 100 vendors. The vulnerability can potentially affect up to one-third of all websites globally. Some vendors were already protected due to changes made after the Rapid Reset vulnerability, while others have implemented patches more recently. The MadeYouReset vulnerability exploits the RST_STREAM frame to trigger protocol violations, prompting the server to reset the stream. This bypasses existing mitigations for similar attacks like Rapid Reset and CONTINUATION Flood. The article discusses the technical details of how MadeYouReset works, its potential impact, and the different approaches vendors are taking to address it.

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