FreeBSD : h2o -- multiple HTTP/2 vulnerabilities (72a5579e-c765-11e9-8052-0028f8d09152) (Ping Flood) (Reset Flood) (Settings Flood)

high Nessus Plugin ID 128135

Language:

New! Plugin Severity Now Using CVSS v3

The calculated severity for Plugins has been updated to use CVSS v3 by default. Plugins that do not have a CVSS v3 score will fall back to CVSS v2 for calculating severity. Severity display preferences can be toggled in the settings dropdown.

Synopsis

The remote FreeBSD host is missing a security-related update.

Description

Jonathon Loomey of Netflix reports :

HTTP/2 implementations do not robustly handle abnormal traffic and resource exhaustion

Recently, a series of DoS attack vulnerabilities have been reported on a broad range of HTTP/2 stacks. Among the vulnerabilities, H2O is exposed to the following :

- CVE-2019-9512 'Ping Flood': The attacker sends continual pings to an HTTP/2 peer, causing the peer to build an internal queue of responses.
Depending on how efficiently this data is queued, this can consume excess CPU, memory, or both, potentially leading to a denial of service.

- CVE-2019-9514 'Reset Flood': The attacker opens a number of streams and sends an invalid request over each stream that should solicit a stream of RST_STREAM frames from the peer. Depending on how the peer queues the RST_STREAM frames, this can consume excess memory, CPU, or both, potentially leading to a denial of service.

- CVE-2019-9515 'Settings Flood': The attacker sends a stream of SETTINGS frames to the peer. Since the RFC requires that the peer reply with one acknowledgement per SETTINGS frame, an empty SETTINGS frame is almost equivalent in behavior to a ping. Depending on how efficiently this data is queued, this can consume excess CPU, memory, or both, potentially leading to a denial of service.

Solution

Update the affected package.

See Also

https://github.com/h2o/h2o/issues/2090

https://www.kb.cert.org/vuls/id/605641/

http://www.nessus.org/u?1d11da2f

Plugin Details

Severity: High

ID: 128135

File Name: freebsd_pkg_72a5579ec76511e980520028f8d09152.nasl

Version: 1.2

Type: local

Published: 8/26/2019

Updated: 1/2/2020

Dependencies: ssh_get_info.nasl

Risk Information

VPR

Risk Factor: Medium

Score: 4.4

CVSS v2

Risk Factor: High

Base Score: 7.8

Temporal Score: 5.8

Vector: AV:N/AC:L/Au:N/C:N/I:N/A:C

Temporal Vector: E:U/RL:OF/RC:C

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Temporal Vector: E:U/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:freebsd:freebsd:h2o-devel, cpe:/o:freebsd:freebsd

Required KB Items: Host/local_checks_enabled, Host/FreeBSD/release, Host/FreeBSD/pkg_info

Exploit Ease: No known exploits are available

Patch Publication Date: 8/25/2019

Vulnerability Publication Date: 8/13/2019

Reference Information

CVE: CVE-2019-9512, CVE-2019-9514, CVE-2019-9515