CyberRota Analysis
AI-GeneratedEnvoy versions prior to 1.36.10, 1.37.6, 1.38.4, and 1.39.1 are vulnerable to a denial-of-service attack due to improper handling of HTTP/2 Host headers, allowing unauthenticated clients to exploit header-copy allocation and potentially exhaust server memory. This can lead to the proxy being killed due to out-of-memory conditions. Organizations using affected versions of Envoy should prioritize upgrading to the patched releases to mitigate this high-severity vulnerability.
Public Exploit Signal
A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.
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Original NVD Description
Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.36.10, 1.37.6, 1.38.4, and 1.39.1, Envoy copies every decoded HTTP/2 Host header value before discarding it when :authority is already present. The discarded value bypasses saveHeader, so its bytes and count are not charged against request header limits. An unauthenticated client can use HPACK indexing to submit many references to a large Host value across a bounded number of streams, forcing extreme header-copy allocation and causing the proxy to be out-of-memory killed. The relevant scope boundary is that the demonstrated amplification uses HTTP/2 HPACK and the duplicate Host discard behavior. This issue is fixed in versions 1.36.10, 1.37.6, 1.38.4, and 1.39.1.
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