CVE-2021-21365
Cross-Site Scripting in Content Rendering
Bootstrap Package is a theme for TYPO3. It has been discovered that rendering content in the website frontend is vulnerable to cross-site scripting. A valid backend user account is needed to exploit this vulnerability. Users of the extension, who have overwritten the affected templates with custom code must manually apply the security fix. Update to version 7.1.2, 8.0.8, 9.1.4, 10.0.10 or 11.0.3 of the Bootstrap Package that fix the problem described. Updated version are available from the TYPO3 extension manager, Packagist and at https://extensions.typo3.org/extension/download/bootstrap_package/.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- Required
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Cross-Site Scripting in Content Rendering
Bootstrap Package is a theme for TYPO3. It has been discovered that rendering content in the website frontend is vulnerable to cross-site scripting. A valid backend user account is needed to exploit this vulnerability. Users of the extension, who have overwritten the affected templates with custom code must manually apply the security fix. Update to version 7.1.2, 8.0.8, 9.1.4, 10.0.10 or 11.0.3 of the Bootstrap Package that fix the problem described. Updated version are available from the TYPO3 extension manager, Packagist and at https://extensions.typo3.org/extension/download/bootstrap_package/.
- Record
CVE-2021-21365- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
EUVDEUVD-2021-0849
Bootstrap Package is a theme for TYPO3. It has been discovered that rendering content in the website frontend is vulnerable to cross-site scripting. A valid backend user account is needed to exploit this vulnerability. Users of the extension, who have overwritten the affected templates with custom code must manually apply the security fix. Update to version 7.1.2, 8.0.8, 9.1.4, 10.0.10 or 11.0.3 of the Bootstrap Package that fix the problem described. Updated version are available from the TYPO3 extension manager, Packagist and at https://extensions.typo3.org/extension/download/bootstrap_package/.
- Record
EUVD-2021-0849- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-p48w-vf3c-rqjx
Cross-Site Scripting in Bootstrap Package
Problem
It has been discovered that rendering content in the website frontend is vulnerable to cross-site scripting. A valid backend user account is needed to exploit this vulnerability.
The following templates are affected by the vulnerability:
Resources/Private/Partials/ContentElements/Carousel/Item/CallToAction.htmlResources/Private/Partials/ContentElements/Carousel/Item/Header.htmlResources/Private/Partials/ContentElements/Carousel/Item/Text.htmlResources/Private/Partials/ContentElements/Carousel/Item/TextAndImage.htmlResources/Private/Partials/ContentElements/Header/SubHeader.html
Users of the extension, who have overwritten the affected templates with custom code must manually apply the security fix as shown in this Git commit.
Solution
Update to version 7.1.2, 8.0.8, 9.0.4, 9.1.3, 10.0.10 or 11.0.3 of the Bootstrap Package that fix the problem described.
Updated version are available from the TYPO3 extension manager, Packagist and at https://extensions.typo3.org/extension/download/bootstrap_package/.
Credits
Thanks to TYPO3 security team member Oliver Hader who reported and fixed the issue.
- Record
GHSA-p48w-vf3c-rqjx- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
NVD
Bootstrap Package is a theme for TYPO3. It has been discovered that rendering content in the website frontend is vulnerable to cross-site scripting. A valid backend user account is needed to exploit this vulnerability. Users of the extension, who have overwritten the affected templates with custom code must manually apply the security fix. Update to version 7.1.2, 8.0.8, 9.1.4, 10.0.10 or 11.0.3 of the Bootstrap Package that fix the problem described. Updated version are available from the TYPO3 extension manager, Packagist and at https://extensions.typo3.org/extension/download/bootstrap_package/.
- Record
CVE-2021-21365- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N - CVSS 2.0
- 3.5 Low
AV:N/AC:M/Au:S/C:N/I:P/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
OSV
Bootstrap Package is a theme for TYPO3. It has been discovered that rendering content in the website frontend is vulnerable to cross-site scripting. A valid backend user account is needed to exploit this vulnerability. Users of the extension, who have overwritten the affected templates with custom code must manually apply the security fix. Update to version 7.1.2, 8.0.8, 9.1.4, 10.0.10 or 11.0.3 of the Bootstrap Package that fix the problem described. Updated version are available from the TYPO3 extension manager, Packagist and at https://extensions.typo3.org/extension/download/bootstrap_package/.
- Record
CVE-2021-21365- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N - Updated
- 2026-11-02
OSVGHSA-p48w-vf3c-rqjx
Cross-Site Scripting in Bootstrap Package
Problem
It has been discovered that rendering content in the website frontend is vulnerable to cross-site scripting. A valid backend user account is needed to exploit this vulnerability.
The following templates are affected by the vulnerability:
Resources/Private/Partials/ContentElements/Carousel/Item/CallToAction.htmlResources/Private/Partials/ContentElements/Carousel/Item/Header.htmlResources/Private/Partials/ContentElements/Carousel/Item/Text.htmlResources/Private/Partials/ContentElements/Carousel/Item/TextAndImage.htmlResources/Private/Partials/ContentElements/Header/SubHeader.html
Users of the extension, who have overwritten the affected templates with custom code must manually apply the security fix as shown in this Git commit.
Solution
Update to version 7.1.2, 8.0.8, 9.0.4, 9.1.3, 10.0.10 or 11.0.3 of the Bootstrap Package that fix the problem described.
Updated version are available from the TYPO3 extension manager, Packagist and at https://extensions.typo3.org/extension/download/bootstrap_package/.
Credits
Thanks to TYPO3 security team member Oliver Hader who reported and fixed the issue.
- Record
GHSA-p48w-vf3c-rqjx- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
OSVBIT-typo3-2021-21365 No score
Bootstrap Package is a theme for TYPO3. It has been discovered that rendering content in the website frontend is vulnerable to cross-site scripting. A valid backend user account is needed to exploit this vulnerability. Users of the extension, who have overwritten the affected templates with custom code must manually apply the security fix. Update to version 7.1.2, 8.0.8, 9.1.4, 10.0.10 or 11.0.3 of the Bootstrap Package that fix the problem described. Updated version are available from the TYPO3 extension manager, Packagist and at https://extensions.typo3.org/extension/download/bootstrap_package/.
- Record
BIT-typo3-2021-21365- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
bk2k/bootstrap-packagePackagist |
7.1.0 up to 7.1.2 | 7.1.2 |
bk2k/bootstrap-packagePackagist |
8.0.0 up to 8.0.8 | 8.0.8 |
bk2k/bootstrap-packagePackagist |
9.0.0 up to 9.0.4 | 9.0.4 |
bk2k/bootstrap-packagePackagist |
9.1.0 up to 9.1.3 | 9.1.3 |
bk2k/bootstrap-packagePackagist |
10.0.0 up to 10.0.10 | 10.0.10 |
bk2k/bootstrap-packagePackagist |
11.0.0 up to 11.0.3 | 11.0.3 |
typo3Bitnami |
before 7.1.2, 8.0.0 up to 8.0.8, 9.0.0 up to 9.0.4, 9.1.0 up to 9.1.3, 10.0.0 up to 10.0.10, 11.0.0 up to 11.0.3 | 7.1.28.0.89.0.49.1.310.0.1011.0.3 |
bk2k/bootstrap-packagePackagist |
7.1.0 up to 7.1.2, plus listed versions 7.1.1 |
7.1.2 |
bk2k/bootstrap-packagePackagist |
8.0.0 up to 8.0.8, plus listed versions 8.0.18.0.28.0.38.0.48.0.58.0.68.0.7 |
8.0.8 |
bk2k/bootstrap-packagePackagist |
9.0.0 up to 9.0.4, plus listed versions 9.0.19.0.29.0.3 |
9.0.4 |
bk2k/bootstrap-packagePackagist |
9.1.0 up to 9.1.3, plus listed versions 9.1.19.1.2 |
9.1.3 |
bk2k/bootstrap-packagePackagist |
10.0.0 up to 10.0.10, plus listed versions 10.0.110.0.210.0.310.0.410.0.5 Show 4 moreShow less10.0.610.0.710.0.810.0.9 |
10.0.10 |
bk2k/bootstrap-packagePackagist |
11.0.0 up to 11.0.3, plus listed versions 11.0.111.0.2 |
11.0.3 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-21365 is a medium vulnerability (CVSS 5.4) in Benjaminkott Bootstrap Package, published April 27, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.94%, the 61st percentile. Fixed in bk2k/bootstrap-package 7.1.2.