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
5.5 Medium
AI Score
Confidence
High
0.0004 Low
EPSS
Percentile
15.5%
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.
Vendor | Product | Version | CPE |
---|---|---|---|
envoyproxy | envoy | * | cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:* |
envoyproxy | envoy | * | cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:* |
envoyproxy | envoy | * | cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:* |
envoyproxy | envoy | * | cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:* |
[
{
"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"
}
]
}
]
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
5.5 Medium
AI Score
Confidence
High
0.0004 Low
EPSS
Percentile
15.5%