CVE-2024-30255

moderate-risk

Published 2024-04-04

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.

Do I need to act?

88.8% chance of exploitation in next 30 days

EPSS score — higher than 11% of all CVEs

Not on CISA KEV list

No confirmed active exploitation reported to CISA

Patch status unknown

Check vendor advisories for fix availability and mitigation guidance

CVSS 5.3/10 Medium

NETWORK / LOW complexity

Affected Products (1)

Envoy

Affected Vendors

Envoyproxy

References (7)

Mailing List http://www.openwall.com/lists/oss-security/2024/04/03/16

Mailing List http://www.openwall.com/lists/oss-security/2024/04/05/3

Patch https://github.com/envoyproxy/envoy/security/advisories/GHSA-j654-3ccm-vfmm

Mailing List http://www.openwall.com/lists/oss-security/2024/04/03/16

Mailing List http://www.openwall.com/lists/oss-security/2024/04/05/3

Patch https://github.com/envoyproxy/envoy/security/advisories/GHSA-j654-3ccm-vfmm

https://www.kb.cert.org/vuls/id/421644

/ 100

moderate-risk

Severity 21/34 · High

Exploitability 20/34 · Moderate

Exposure 5/34 · Minimal