Remote code execution in kramdown gem for Ruby

1) Improper Neutralization of Special Elements in Output Used by a Downstream Component

EUVDB-ID: #VU31897

Risk: High

CVSSv3.1: 8.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-14001

CWE-ID: CWE-74 - Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')

Exploit availability: No

Description

The vulnerability allows a remote attacker to execute arbitrary code on the system.

The vulnerability exists due to improper validation of input. A remote attacker can gain read access (such as template="/etc/passwd") or embedded Ruby code execution (such as a string that begins with template="string://<%= `).

Mitigation

Install update from vendor's website.

Vulnerable software versions

kramdown: 0.1.0 - 2.2.1

External links

http://github.com/gettalong/kramdown
http://github.com/gettalong/kramdown/commit/1b8fd33c3120bfc6e5164b449e2c2fc9c9306fde
http://github.com/gettalong/kramdown/compare/REL_2_2_1...REL_2_3_0
http://kramdown.gettalong.org
http://kramdown.gettalong.org/news.html
http://rubygems.org/gems/kramdown

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.