Link following in Helm

1) Link following

EUVDB-ID: #VU30626

Risk: High

CVSSv4.0: 8.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2019-18658

CWE-ID: CWE-59 - Improper Link Resolution Before File Access ('Link Following')

Exploit availability: No

Description

The vulnerability allows a remote non-authenticated attacker to execute arbitrary code.

In Helm 2.x before 2.15.2, commands that deal with loading a chart as a directory or packaging a chart provide an opportunity for a maliciously designed chart to include sensitive content such as /etc/passwd, or to execute a denial of service (DoS) via a special file such as /dev/urandom, via symlinks. No version of Tiller is known to be impacted. This is a client-only issue.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Helm: 2.0.0 - 2.15.1

CPE2.3

• cpe:2.3:a:the_helm_project:helm:2.0.0:*:*:*:*:*:*:*
• cpe:2.3:a:the_helm_project:helm:2.0.1:*:*:*:*:*:*:*
• cpe:2.3:a:the_helm_project:helm:2.0.2:*:*:*:*:*:*:*

External links

https://helm.sh/blog/2019-10-30-helm-symlink-security-notice/

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.