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Vulnerability details: VCID-he5m-6wj4-rbhc
Vulnerability ID VCID-he5m-6wj4-rbhc
Aliases CVE-2021-21357
GHSA-3vg7-jw9m-pc3f
Summary Broken Access Control in Form Framework ### Problem Due to improper input validation, attackers can by-pass restrictions of predefined options and submit arbitrary data in the Form Designer backend module of the Form Framework. In the default configuration of the Form Framework this allows attackers to explicitly allow arbitrary mime-types for file uploads - however, default _fileDenyPattern_ successfully blocked files like _.htaccess_ or _malicious.php_. Besides that, attackers can persist those files in any writable directory of the corresponding TYPO3 installation. A valid backend user account with access to the form module is needed to exploit this vulnerability. ### Solution Update to TYPO3 versions 8.7.40, 9.5.25, 10.4.14, 11.1.1 that fix the problem described. ### Credits Thanks to Richie Lee who reported this issue and to TYPO3 contributor Ralf Zimmermann who fixed the issue. ### References * [TYPO3-CORE-SA-2021-003](https://typo3.org/security/advisory/typo3-core-sa-2021-003)
Status Published
Exploitability 0.5
Weighted Severity 8.0
Risk 4.0
Affected and Fixed Packages Package Details
Weaknesses (5)
System Score Found at
epss 0.01121 https://api.first.org/data/v1/epss?cve=CVE-2021-21357
epss 0.01121 https://api.first.org/data/v1/epss?cve=CVE-2021-21357
epss 0.01121 https://api.first.org/data/v1/epss?cve=CVE-2021-21357
epss 0.01121 https://api.first.org/data/v1/epss?cve=CVE-2021-21357
epss 0.01121 https://api.first.org/data/v1/epss?cve=CVE-2021-21357
epss 0.01121 https://api.first.org/data/v1/epss?cve=CVE-2021-21357
epss 0.01121 https://api.first.org/data/v1/epss?cve=CVE-2021-21357
epss 0.01121 https://api.first.org/data/v1/epss?cve=CVE-2021-21357
epss 0.01121 https://api.first.org/data/v1/epss?cve=CVE-2021-21357
cvssv3.1_qr HIGH https://github.com/advisories/GHSA-3vg7-jw9m-pc3f
cvssv3.1 8.3 https://github.com/FriendsOfPHP/security-advisories/blob/master/typo3/cms-core/CVE-2021-21357.yaml
generic_textual HIGH https://github.com/FriendsOfPHP/security-advisories/blob/master/typo3/cms-core/CVE-2021-21357.yaml
cvssv3.1 8.3 https://github.com/FriendsOfPHP/security-advisories/blob/master/typo3/cms/CVE-2021-21357.yaml
generic_textual HIGH https://github.com/FriendsOfPHP/security-advisories/blob/master/typo3/cms/CVE-2021-21357.yaml
cvssv3.1 8.3 https://github.com/TYPO3/TYPO3.CMS/security/advisories/GHSA-3vg7-jw9m-pc3f
cvssv3.1_qr HIGH https://github.com/TYPO3/TYPO3.CMS/security/advisories/GHSA-3vg7-jw9m-pc3f
generic_textual HIGH https://github.com/TYPO3/TYPO3.CMS/security/advisories/GHSA-3vg7-jw9m-pc3f
cvssv3.1 8.3 https://nvd.nist.gov/vuln/detail/CVE-2021-21357
generic_textual HIGH https://nvd.nist.gov/vuln/detail/CVE-2021-21357
cvssv3.1 8.3 https://packagist.org/packages/typo3/cms-form
generic_textual HIGH https://packagist.org/packages/typo3/cms-form
cvssv3.1 8.3 https://typo3.org/security/advisory/typo3-core-sa-2021-003
generic_textual HIGH https://typo3.org/security/advisory/typo3-core-sa-2021-003
No exploits are available.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:H/E:H/RL:O/RC:C Found at https://github.com/FriendsOfPHP/security-advisories/blob/master/typo3/cms-core/CVE-2021-21357.yaml
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:H/E:H/RL:O/RC:C Found at https://github.com/FriendsOfPHP/security-advisories/blob/master/typo3/cms/CVE-2021-21357.yaml
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:H/E:H/RL:O/RC:C Found at https://github.com/TYPO3/TYPO3.CMS/security/advisories/GHSA-3vg7-jw9m-pc3f
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:H/E:H/RL:O/RC:C Found at https://nvd.nist.gov/vuln/detail/CVE-2021-21357
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:H/E:H/RL:O/RC:C Found at https://packagist.org/packages/typo3/cms-form
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:H/E:H/RL:O/RC:C Found at https://typo3.org/security/advisory/typo3-core-sa-2021-003
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none

Exploit Prediction Scoring System (EPSS)
Percentile 0.78191
EPSS Score 0.01121
Published At April 1, 2026, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2026-04-01T13:01:49.092194+00:00 GithubOSV Importer Import https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2021/03/GHSA-3vg7-jw9m-pc3f/GHSA-3vg7-jw9m-pc3f.json 38.0.0