SB2019081927 - Fedora 30 update for mod_http2

Description

This security bulletin contains information about 3 secuirty vulnerabilities.

1) Resource exhaustion (CVE-ID: CVE-2019-9511)

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. 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 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.

3) 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.

References

• https://bodhi.fedoraproject.org/updates/FEDORA-2019-63ba15cc83