CVE-2020-15187: 
Helm vulnerability analysis and mitigation

CVE-2020-15187 affects Helm versions before 2.16.11 and 3.3.2. The vulnerability was discovered during a security audit of Helm's codebase and disclosed on September 17, 2020. The issue affects the plugin system in Helm, a package manager for Kubernetes Charts, where a plugin can contain duplicates of the same entry, with the last one always being used (Helm Advisory).

The vulnerability stems from improper validation of plugin.yaml files, allowing duplicate entries to exist within the same plugin configuration. When parsing plugin metadata files, Helm would accept duplicate entries and use the last occurrence, creating a potential security weakness. The vulnerability has been assigned a CVSS v3.1 Base Score of 4.7 (MEDIUM) with vector CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L by NVD, though GitHub initially rated it as LOW with vector CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:N/I:L/A:N (NVD).

If exploited, this vulnerability could allow an attacker to modify a plugin's install hooks, potentially leading to local code execution. The impact is contingent on an attacker having write access to either the git repository or plugin archive (.tgz) during the download process, which could occur during a man-in-the-middle attack on a non-SSL connection (Helm Advisory).

The vulnerability requires specific conditions to be exploitable. An attacker must have write access to the git repository or plugin archive while it's being downloaded, which typically occurs during a man-in-the-middle attack on a non-SSL connection. The attack surface is limited by the requirement of these specific conditions (Helm Advisory).

The vulnerability has been patched in Helm versions 2.16.11 and 3.3.2. For users unable to upgrade immediately, the recommended workaround is to ensure plugins are installed using a secure connection protocol like SSL. The fix involved switching to stricter YAML parsing on plugin metadata files to prevent duplicate entries (Helm Advisory, Helm Commit).