Vulnerability in less-openui5 (CVE-2021-21316)
Summary
Vulnerability in less-openui5 (CVE-2021-21316). Successful exploitation can lead to full system takeover. Mitigation: upgrade to 0.10.0 or later.
Original description
The description as published by the source.
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.
Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2021-21316 has been found in less-openui5.
Successful exploitation can lead to full system takeover.
What to do: upgrade less-openui5 to 0.10.0 or later.
If unsure, ask your IT team or search "less-openui5 CVE-2021-21316" on the vendor's site.
CVE-2021-21316 (less-openui5) — CWE-74
Attack vector: local / unauthenticated
Patched: 0.10.0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-74) exists in less-openui5.
Check the vendor advisory for the affected versions of less-openui5.
Severity: ?. Successful exploitation can lead to full system takeover.
Update to 0.10.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'less-openui5' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'less-openui5' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
less-openui5を grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade less-openui5 to 0.10.0ステージング環境で 0.10.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
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3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory github.com
- advisory nvd.nist.gov
- advisory github.com
- advisory npmjs.com
- advisory lesscss.org
- patch github.com