Amazon Linux 2 : mod_http2 (ALAS-2019-1342) (0-Length Headers Leak) (Data Dribble) (Internal Data Buffering)

High Nessus Plugin ID 130401

New! Vulnerability Priority Rating (VPR)

Tenable calculates a dynamic VPR for every vulnerability. VPR combines vulnerability information with threat intelligence and machine learning algorithms to predict which vulnerabilities are most likely to be exploited in attacks. Read more about what VPR is and how it's different from CVSS.

VPR Score: 5.1

Synopsis

The remote Amazon Linux 2 host is missing a security update.

Description

Some HTTP/2 implementations are vulnerable to window size manipulation and stream prioritization manipulation, potentially leading to a denial of service. The attacker requests a large amount of data from a specified resource over multiple streams. They manipulate window size and stream priority to force the server to queue the data in 1-byte chunks. Depending on how efficiently this data is queued, this can consume excess CPU, memory, or both.(CVE-2019-9511)

Some HTTP/2 implementations are vulnerable to a header leak, potentially leading to a denial of service. The attacker sends a stream of headers with a 0-length header name and 0-length header value, optionally Huffman encoded into 1-byte or greater headers. Some implementations allocate memory for these headers and keep the allocation alive until the session dies. This can consume excess memory.(CVE-2019-9516)

Some HTTP/2 implementations are vulnerable to unconstrained interal data buffering, potentially leading to a denial of service. The attacker opens 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.(CVE-2019-9517)

Solution

Run 'yum update mod_http2' to update your system.

See Also

https://alas.aws.amazon.com/AL2/ALAS-2019-1342.html

Plugin Details

Severity: High

ID: 130401

File Name: al2_ALAS-2019-1342.nasl

Version: 1.2

Type: local

Agent: unix

Published: 2019/10/31

Updated: 2019/12/17

Dependencies: 12634

Risk Information

Risk Factor: High

VPR Score: 5.1

CVSS v2.0

Base Score: 7.8

Temporal Score: 5.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C

Temporal Vector: CVSS2#E:U/RL:OF/RC:C

CVSS v3.0

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: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:mod_http2, p-cpe:/a:amazon:linux:mod_http2-debuginfo, cpe:/o:amazon:linux:2

Required KB Items: Host/local_checks_enabled, Host/AmazonLinux/release, Host/AmazonLinux/rpm-list

Exploit Ease: No known exploits are available

Patch Publication Date: 2019/10/30

Vulnerability Publication Date: 2019/08/13

Reference Information

CVE: CVE-2019-9511, CVE-2019-9516, CVE-2019-9517

ALAS: 2019-1342