CVE-2024-30255

HTTP/2: CPU exhaustion due to CONTINUATION frame flood

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.

Category

5.3
CVSS
Severity: Medium
CVSS 3.1 •
EPSS 91.84% Top 5%
Affected: envoyproxy envoy
Published at:
Updated at:

References

Link Tags
https://github.com/envoyproxy/envoy/security/advisories/GHSA-j654-3ccm-vfmm
http://www.openwall.com/lists/oss-security/2024/04/05/3
http://www.openwall.com/lists/oss-security/2024/04/03/16

Frequently Asked Questions

What is the severity of CVE-2024-30255?
CVE-2024-30255 has been scored as a medium severity vulnerability.
How to fix CVE-2024-30255?
To fix CVE-2024-30255, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2024-30255 being actively exploited in the wild?
It is possible that CVE-2024-30255 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~92% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2024-30255?
CVE-2024-30255 affects envoyproxy envoy.
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