Vulnerability in Less-Openui5 Project

CVE-2021-21316

less-openui5 is an npm package which enables building OpenUI5 themes with Less.js. In less-openui5 before version 0.10., when processing theming resources (i.e. `*.less` files) with less-openui5 that originate from an untrusted source, those resources might contain JavaScript code which will be executed in the context of the build process. While this is a feature of the Less.js library it is an unexpected behavior in the context of OpenUI5 and SAPUI5 development. Especially in the context of UI5 Tooling which relies on less-openui5. An attacker might create a library or theme-library containing a custom control or theme, hiding malicious JavaScript code in one of the .less files. Refer to the referenced GHSA-3crj-w4f5-gwh4 for examples. Starting with Less.js version 3.0.0, the Inline JavaScript feature is disabled by default. less-openui5 however currently uses a fork of Less.js v1.6.3. Note that disabling the Inline JavaScript feature in Less.js versions 1.x, still evaluates code has additional double codes around it. We decided to remove the inline JavaScript evaluation feature completely from the code of our Less.js fork. This fix is available in less-openui5 version 0.10.0.

EPSS: 0.010 (58.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.3 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:N/I:H/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2021-21316?
CVE-2021-21316 is a medium-severity vulnerability in Less-Openui5 Project, classified under Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection). CVSS score: 6.3/10. Published 2021-02-16.
How severe is CVE-2021-21316?
Medium severity. CVSS v3 base score is 6.3 out of 10.