HTTP/2: CPU exhaustion due to CONTINUATION frame flood
Envoy is a cloud-native, open source edge and service proxy. The HTTP/2 protocol stack in Envoy versions prior to 1.29.3, 1.28.2, 1.27.4, and 1.26.8 are vulnerable to CPU exhaustion due to flood of CONTINUATION frames. Envoy's HTTP/2 codec allows the client to send an unlimited number of CONTINUATION frames even after exceeding Envoy's header map limits. This allows an attacker to send a sequence of CONTINUATION frames without the END_HEADERS bit set causing CPU utilization, consuming approximately 1 core per 300Mbit/s of traffic and culminating in denial of service through CPU exhaustion. Users should upgrade to version 1.29.3, 1.28.2, 1.27.4, or 1.26.8 to mitigate the effects of the CONTINUATION flood. As a workaround, disable HTTP/2 protocol for downstream connections.
describes (1)
Related CVEs.
| ID | severity | exploitable | ||
|---|---|---|---|---|
| CVE-2024-30255US | high7.5 | Exploit | ||
Envoy is a cloud-native, open source edge and service proxy. The HTTP/2 protocol stack in Envoy versions prior to 1.29.3, 1.28.2, 1.27.4, and 1.26.8 are vulnerable to CPU exhaustio… | ||||
references
External citations — patches, advisories, analysis.
- http://www.openwall.com/lists/oss-security/2024/04/03/16ADVISORY
- http://www.openwall.com/lists/oss-security/2024/04/05/3DISCUSSION
- https://github.com/envoyproxy/envoy/security/advisories/GHSA-j654-3ccm-vfmmADVISORY
- https://nvd.nist.gov/vuln/detail/CVE-2024-30255WEB
- https://www.kb.cert.org/vuls/id/421644WEB
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