SB2019100121 - Red Hat update for Red Hat JBoss Core Services Apache HTTP Server 2.4.29 SP3



SB2019100121 - Red Hat update for Red Hat JBoss Core Services Apache HTTP Server 2.4.29 SP3

Published: October 1, 2019

Security Bulletin ID SB2019100121
Severity
Medium
Patch available
YES
Number of vulnerabilities 2
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 2 secuirty vulnerabilities.


1) Resource exhaustion (CVE-ID: CVE-2019-9516)

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to improper input validation when processing HTTP/2 requests within the ngx_http_v2_module module. A remote attacker can send a specially crafted HTTP/2 request the affected server, consume all available CPU resources and perform a denial of service (DoS) attack.

Successful exploitation of the vulnerability requires that support for HTTP/2 is enabled.


2) Resource management error (CVE-ID: CVE-2019-9517)

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to incorrect implementation of HTTP/2 protocol. A remote attacker can  open the HTTP/2 window so the peer can send without constraint; however, they leave the TCP window closed so the peer cannot actually write (many of) the bytes on the wire. The attacker then sends a stream of requests for a large response object. Depending on how the servers queue the responses, this can consume excess memory, CPU, or both.

Remediation

Install update from vendor's website.