Vulnerability · Published Apr 4, 2024 · Assigned by GitHub_M
CVE-2024-30255HTTP/2: CPU exhaustion due to CONTINUATION frame flood
Medium 5.3
In plain English
A medium-severity security flaw in envoy from envoyproxy. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 85.0% (higher than 99.7% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code.
Official description
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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| envoyproxy | envoy | >= 1.29.0, < 1.29.3>= 1.28.0, < 1.28.2>= 1.27.0, < 1.27.4< 1.26.8 |
Weakness: CWE-390 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L