CVE-2024-30255 HTTP/2: CPU exhaustion due to CONTINUATION frame flood

2024-04-0419:41:02

CWE-390

GitHub_M

www.cve.org

envoy

http/2

cpu exhaustion

continuation frames

vulnerability

upgrade

downstream connections

5.3 Medium

CVSS3

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

LOW

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

5.8 Medium

AI Score

Confidence

High

0.0004 Low

EPSS

Percentile

15.5%

JSON

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.

CNA Affected

[
  {
    "vendor": "envoyproxy",
    "product": "envoy",
    "versions": [
      {
        "version": ">= 1.29.0, < 1.29.3",
        "status": "affected"
      },
      {
        "version": ">= 1.28.0, < 1.28.2",
        "status": "affected"
      },
      {
        "version": ">= 1.27.0, < 1.27.4",
        "status": "affected"
      },
      {
        "version": "< 1.26.8",
        "status": "affected"
      }
    ]
  }
]