CVE-2015-1855

Name: CVE-2015-1855
Creator: NVD / NIST
Published: 2019-11-29T21:15:10.807+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.9/10EPSS 2.81%

Last modified Jun 17, 2026

CVE-2015-1855 is a medium-severity vulnerability rated 5.9/10 on the CVSS scale. verify_certificate_identity in the OpenSSL extension in Ruby before 2.0.0 patchlevel 645, 2.1.x before 2.1.6, and 2.2.x before 2.2.2 does not properly validate hostnames, which allows remote attackers to spoof servers via vectors related to (1) multiple wildcards, (1) wildcards in IDNA names, (3) case sensitivity, and (4) non-ASCII characters.. EPSS estimates a 2.81% chance of exploitation in the next 30 days.

Description

verify_certificate_identity in the OpenSSL extension in Ruby before 2.0.0 patchlevel 645, 2.1.x before 2.1.6, and 2.2.x before 2.2.2 does not properly validate hostnames, which allows remote attackers to spoof servers via vectors related to (1) multiple wildcards, (1) wildcards in IDNA names, (3) case sensitivity, and (4) non-ASCII characters.

Metrics

CVSS 3.1

5.9/10

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

EPSS Probability

2.81%

84.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-20

Affected Software

Vendor	Product	Versions
Ruby-Lang	Ruby	>= 2.1.0, < 2.1.6
Ruby-Lang	Ruby	>= 2.2.0, < 2.2.2
Ruby-Lang	Ruby	2.0.0
Ruby-Lang	Trunk	< 50292
Debian	Debian Linux	7.0
Debian	Debian Linux	8.0
Debian	Debian Linux	9.0
Puppet	Puppet Agent	1.0.0
Puppet	Puppet Enterprise	>= 3.0.0, < 3.8.0

References

http://www.debian.org/security/2015/dsa-3245Third Party Advisory
http://www.debian.org/security/2015/dsa-3246Third Party Advisory
http://www.debian.org/security/2015/dsa-3247Third Party Advisory
https://bugs.ruby-lang.org/issues/9644Third Party Advisory
https://puppetlabs.com/security/cve/cve-2015-1855Third Party Advisory
https://www.ruby-lang.org/en/news/2015/04/13/ruby-openssl-hostname-matching-vulnerability/Vendor Advisory
http://www.debian.org/security/2015/dsa-3245Third Party Advisory
http://www.debian.org/security/2015/dsa-3246Third Party Advisory
http://www.debian.org/security/2015/dsa-3247Third Party Advisory
https://bugs.ruby-lang.org/issues/9644Third Party Advisory
https://puppetlabs.com/security/cve/cve-2015-1855Third Party Advisory
https://www.ruby-lang.org/en/news/2015/04/13/ruby-openssl-hostname-matching-vulnerability/Vendor Advisory

Timeline

Published: Nov 29, 2019
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2015-1855?

How severe is CVE-2015-1855?

CVE-2015-1855 has a CVSS score of 5.9/10 (MEDIUM severity). The EPSS model estimates a 2.81% probability of exploitation in the next 30 days.

How do I fix CVE-2015-1855?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2015-1855?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST