FreeBSD : ruby -- multiple vulnerabilities (eb69bcf2-18ef-4aa2-bb0c-83b263364089)

critical Nessus Plugin ID 108739

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Synopsis

The remote FreeBSD host is missing one or more security-related updates.

Description

Ruby news :

CVE-2017-17742: HTTP response splitting in WEBrick

If a script accepts an external input and outputs it without modification as a part of HTTP responses, an attacker can use newline characters to deceive the clients that the HTTP response header is stopped at there, and can inject fake HTTP responses after the newline characters to show malicious contents to the clients.

CVE-2018-6914: Unintentional file and directory creation with directory traversal in tempfile and tmpdir

Dir.mktmpdir method introduced by tmpdir library accepts the prefix and the suffix of the directory which is created as the first parameter. The prefix can contain relative directory specifiers '../', so this method can be used to target any directory. So, if a script accepts an external input as the prefix, and the targeted directory has inappropriate permissions or the ruby process has inappropriate privileges, the attacker can create a directory or a file at any directory.

CVE-2018-8777: DoS by large request in WEBrick

If an attacker sends a large request which contains huge HTTP headers, WEBrick try to process it on memory, so the request causes the out-of-memory DoS attack.

CVE-2018-8778: Buffer under-read in String#unpack

String#unpack receives format specifiers as its parameter, and can be specified the position of parsing the data by the specifier @. If a big number is passed with @, the number is treated as the negative value, and out-of-buffer read is occurred. So, if a script accepts an external input as the argument of String#unpack, the attacker can read data on heaps.

CVE-2018-8779: Unintentional socket creation by poisoned NUL byte in UNIXServer and UNIXSocket

UNIXServer.open accepts the path of the socket to be created at the first parameter. If the path contains NUL (\0) bytes, this method recognize that the path is completed before the NUL bytes. So, if a script accepts an external input as the argument of this method, the attacker can make the socket file in the unintentional path. And, UNIXSocket.open also accepts the path of the socket to be created at the first parameter without checking NUL bytes like UNIXServer.open.
So, if a script accepts an external input as the argument of this method, the attacker can accepts the socket file in the unintentional path.

CVE-2018-8780: Unintentional directory traversal by poisoned NUL byte in Dir

Dir.open, Dir.new, Dir.entries and Dir.empty? accept the path of the target directory as their parameter. If the parameter contains NUL (\0) bytes, these methods recognize that the path is completed before the NUL bytes. So, if a script accepts an external input as the argument of these methods, the attacker can make the unintentional directory traversal.

Solution

Update the affected packages.

See Also

https://www.ruby-lang.org/en/news/2018/03/28/ruby-2-5-1-released/

https://www.ruby-lang.org/en/news/2018/03/28/ruby-2-4-4-released/

https://www.ruby-lang.org/en/news/2018/03/28/ruby-2-3-7-released/

http://www.nessus.org/u?71079310

http://www.nessus.org/u?78bd7fa9

http://www.nessus.org/u?e4a4feab

http://www.nessus.org/u?1b770e41

http://www.nessus.org/u?95c4af25

http://www.nessus.org/u?23857932

http://www.nessus.org/u?4e3e020f

Plugin Details

Severity: Critical

ID: 108739

File Name: freebsd_pkg_eb69bcf218ef4aa2bb0c83b263364089.nasl

Version: 1.6

Type: local

Published: 3/30/2018

Updated: 7/10/2019

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 5.2

CVSS v2

Risk Factor: High

Base Score: 7.5

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

CVSS v3

Risk Factor: Critical

Base Score: 9.1

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

Vulnerability Information

CPE: p-cpe:/a:freebsd:freebsd:ruby, cpe:/o:freebsd:freebsd

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

Patch Publication Date: 3/29/2018

Vulnerability Publication Date: 3/28/2018

Reference Information

CVE: CVE-2017-17742, CVE-2018-6914, CVE-2018-8777, CVE-2018-8778, CVE-2018-8779, CVE-2018-8780