CVE-2017-17742: Medium severity Apple macOS Mojave vulnerability

Published Mar 28, 2018
·
Updated

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.

Affected versions:

Ruby 2.2 series: 2.2.9 and earlier Ruby 2.3 series: 2.3.6 and earlier Ruby 2.4 series: 2.4.3 and earlier Ruby 2.5 series: 2.5.0 and earlier

External References:

https://www.ruby-lang.org/en/news/2018/03/28/http-response-splitting-in-webrick-cve-2017-17742/

Other sources

It was found that WEBrick did not sanitize headers sent back to clients, resulting in a response-splitting vulnerability. An attacker, able to control the server's headers, could force WEBrick into injecting additional headers to a client.

Ruby before 2.2.10, 2.3.x before 2.3.7, 2.4.x before 2.4.4, 2.5.x before 2.5.1, and 2.6.0-preview1 allows an HTTP Response Splitting attack. An attacker can inject a crafted key and value into an HTTP response for the HTTP server of WEBrick.

Ruby. Multiple issues in Ruby were addressed in this update.

Credit

CVE-2017-0898, CVE-2017-10784, CVE-2017-14033, CVE-2017-14064, CVE-2017-17405, CVE-2017-17742, CVE-2018-6914, CVE-2018-8777, CVE-2018-8778, CVE-2018-8779, CVE-2018-8780

Affected Software

25 affected componentsFixes available
redhat/ruby<0:2.0.0.648-36.el7
0:2.0.0.648-36.el7
redhat/ruby<0:2.0.0.648-36.el7_4
0:2.0.0.648-36.el7_4
redhat/ruby<0:2.0.0.648-36.el7_5
0:2.0.0.648-36.el7_5
redhat/ruby<0:2.0.0.648-37.el7_6
0:2.0.0.648-37.el7_6
redhat/rh-ruby23-ruby<0:2.3.8-69.el6
0:2.3.8-69.el6
redhat/rh-ruby24-ruby<0:2.4.5-91.el6
0:2.4.5-91.el6
redhat/rh-ruby23-ruby<0:2.3.8-69.el7
0:2.3.8-69.el7
redhat/rh-ruby24-ruby<0:2.4.5-91.el7
0:2.4.5-91.el7
redhat/rh-ruby25-ruby<0:2.5.3-6.el7
0:2.5.3-6.el7
redhat/ruby<2.2.10
2.2.10
redhat/ruby<2.3.7
2.3.7
redhat/ruby<2.4.4
2.4.4
redhat/ruby<2.5.1
2.5.1
Apple macOS Mojave<10.14.1
10.14.1
Apple High Sierra
Apple Sierra
Apple macOS High Sierra<10.13.6
10.13.6
Apple El Capitan
ruby-lang Ruby>=2.2.0<2.2.10
ruby-lang Ruby>=2.3.0<2.3.7
ruby-lang Ruby>=2.4.0<2.4.4
ruby-lang Ruby>=2.5.0<2.5.1
ruby-lang Ruby=2.6.0-preview1
Debian Debian Linux=7.0
debian/jruby
9.3.9.0+ds-89.4.8.0+ds-3

Remediation

Information

The server can manually sanitize possibly untrusted headers prior to inserting them in the reply.

Event History

Mar 28, 2018
CVE Published
12:00 AM
Apr 3, 2018
CVE Published
via MITRE·12:00 AM
Data Sourced
via MITRE·12:00 AM
Description
Jan 11, 2024
Data Sourced
via Launchpad·10:34 PM
Description
Feb 19, 2026
Data Sourced
via Ubuntu·07:39 PM
RemedyDescriptionSeverityAffected Software
Data Sourced
via Debian·07:40 PM
DescriptionAffected Software
Free Weekly Intel

Don't miss critical vulnerabilities

Join thousands of security professionals who receive our weekly digest of trending CVEs, zero-days, and exploited vulnerabilities.

No spam. Unsubscribe anytime.

Frequently Asked Questions

1

What is CVE-2017-17742?

CVE-2017-17742 is a vulnerability in Ruby that allows an HTTP Response Splitting attack.

2

What is the severity of CVE-2017-17742?

CVE-2017-17742 has a severity rating of medium (5.3).

3

Which versions of Ruby are affected by CVE-2017-17742?

Ruby versions before 2.2.10, 2.3.x before 2.3.7, 2.4.x before 2.4.4, 2.5.x before 2.5.1, and 2.6.0-preview1 are affected by CVE-2017-17742.

4

How can I fix the CVE-2017-17742 vulnerability in Ruby?

To fix the CVE-2017-17742 vulnerability in Ruby, update to version 2.2.10, 2.3.7, 2.4.4, 2.5.1, or a later version.

5

Where can I find more information about CVE-2017-17742?

You can find more information about CVE-2017-17742 at the following references: [Link 1](https://www.ruby-lang.org/en/news/2018/03/28/http-response-splitting-in-webrick-cve-2017-17742/), [Link 2](https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=1561957), [Link 3](https://access.redhat.com/security/updates/classification/).

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203