CVE-2023-39325

2023-10-1117:12:30

redhat.com

access.redhat.com

135

http/2

rapid reset attack

denial of service

server resource consumption

red hat

cisa

cve-2023-39325

golang

CVSS3

7.5

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

HIGH

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

EPSS

0.813

Percentile

98.4%

JSON

A flaw was found in handling multiplexed streams in the HTTP/2 protocol. A client can repeatedly make a request for a new multiplex stream and immediately send an RST_STREAM frame to cancel it. This creates extra work for the server setting up and tearing down the streams while not hitting any server-side limit for the maximum number of active streams per connection, resulting in a denial of service due to server resource consumption. Red Hat has rated the severity of this flaw as ‘Important’ as the US Cybersecurity and Infrastructure Security Agency (CISA) declared this vulnerability an active exploit. CVE-2023-39325 was assigned for the Rapid Reset Attack in the Go language packages.

Mitigation

The default stream concurrency limit in golang is 250 streams (requests) per HTTP/2 connection. This value may be adjusted in the golang.org/x/net/http2 package using the Server.MaxConcurrentStreams setting and the ConfigureServer function which are available in golang.org/x/net/http2.