Cross-Site Scripting (XSS) in typo3/cms-core (CVE-2021-32768)
Summary
Cross-site scripting in typo3/cms-core (CVE-2021-32768). Risk of unauthorized operations or information disclosure. Exploitable via lib.parseFunc. Mitigation: upgrade to 9.5.29 or later.
Original description
The description as published by the source.
Meta
- CVSS:
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N/E:F/RL:O/RC(5.7)
Problem
Failing to properly parse, sanitize and encode malicious rich-text content, the content rendering process in the website frontend is vulnerable to cross-site scripting. Corresponding rendering instructions via TypoScript functionality HTMLparser do not consider all potentially malicious HTML tag & attribute combinations per default.
In addition, the lack of comprehensive default node configuration for rich-text fields in the backend user interface fosters this malfunction.
In default scenarios, a valid backend user account is needed to exploit this vulnerability. In case custom plugins used in the website frontend accept and reflect rich-text content submitted by users, no authentication is required.
Solution
Update to TYPO3 versions 7.6.53 ELTS, 8.7.42 ELTS, 9.5.29, 10.4.19, 11.3.2 that fix the problem described above.
Custom package typo3/html-sanitizer - based on allow-lists only - takes care of sanitizing potentially malicious markup. The default behavior is based on safe and commonly used markup - however, this can be extended or restricted further in case it is necessary for individual scenarios.
During the frontend rendering process, sanitization is applied to the default TypoScript path lib.parseFunc, which is implicitly us…
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-2021-32768 has been found in typo3/cms-core.
Attackers can target a specific entry point like lib.parseFunc over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: upgrade typo3/cms-core to 9.5.29 or later.
If unsure, ask your IT team or search "typo3/cms-core CVE-2021-32768" on the vendor's site.
CVE-2021-32768 (typo3/cms-core) — CWE-79
Attack vector: remote (network-reachable) / unauthenticated
Attack surface: lib.parseFunc
Patched: 9.5.29 — 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.
Cross-site scripting (XSS) (CWE-79) exists in typo3/cms-core. Attackers reach the vulnerable code path via lib.parseFunc without authentication.
Check the vendor advisory for the affected versions of typo3/cms-core. Attack surface: lib.parseFunc.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to 9.5.29.
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 'typo3/cms-core' . 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
-
1Identify exposure identify
grep -r 'typo3/cms-core' . | 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
typo3/cms-core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 typo3/cms-core to 9.5.29ステージング環境で 9.5.29 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。
-
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 nvd.nist.gov
- web github.com
- web github.com
- web github.com
- web github.com
- web typo3.org