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Vulnerability details: VCID-5jgb-dsyx-hyb4
Vulnerability ID VCID-5jgb-dsyx-hyb4
Aliases CVE-2021-21338
GHSA-4jhw-2p6j-5wmp
Summary Open Redirection in Login Handling ### Problem It has been discovered that Login Handling is susceptible to open redirection which allows attackers redirecting to arbitrary content, and conducting phishing attacks. No authentication is required in order to exploit this vulnerability. ### Solution Update to TYPO3 versions 6.2.57, 7.6.51, 8.7.40, 9.5.25, 10.4.14, 11.1.1 that fix the problem described. ### Credits Thanks to Alexander Kellner who reported this issue and to TYPO3 security team member Torben Hansen who fixed the issue. ### References * [TYPO3-CORE-SA-2021-001](https://typo3.org/security/advisory/typo3-core-sa-2021-001)
Status Published
Exploitability 0.5
Weighted Severity 6.2
Risk 3.1
Affected and Fixed Packages Package Details
Weaknesses (3)
CWE-601 URL Redirection to Untrusted Site ('Open Redirect')
CWE-1035 OWASP Top Ten 2017 Category A9 - Using Components with Known Vulnerabilities
CWE-937 OWASP Top Ten 2013 Category A9 - Using Components with Known Vulnerabilities
System Score Found at
epss 0.00253 https://api.first.org/data/v1/epss?cve=CVE-2021-21338
epss 0.00253 https://api.first.org/data/v1/epss?cve=CVE-2021-21338
epss 0.00253 https://api.first.org/data/v1/epss?cve=CVE-2021-21338
epss 0.00253 https://api.first.org/data/v1/epss?cve=CVE-2021-21338
epss 0.00253 https://api.first.org/data/v1/epss?cve=CVE-2021-21338
epss 0.00253 https://api.first.org/data/v1/epss?cve=CVE-2021-21338
epss 0.00253 https://api.first.org/data/v1/epss?cve=CVE-2021-21338
epss 0.00253 https://api.first.org/data/v1/epss?cve=CVE-2021-21338
epss 0.00253 https://api.first.org/data/v1/epss?cve=CVE-2021-21338
cvssv3.1_qr MODERATE https://github.com/advisories/GHSA-4jhw-2p6j-5wmp
cvssv3.1 6.1 https://github.com/FriendsOfPHP/security-advisories/blob/master/typo3/cms-core/CVE-2021-21338.yaml
generic_textual MODERATE https://github.com/FriendsOfPHP/security-advisories/blob/master/typo3/cms-core/CVE-2021-21338.yaml
cvssv3.1 6.1 https://github.com/FriendsOfPHP/security-advisories/blob/master/typo3/cms/CVE-2021-21338.yaml
generic_textual MODERATE https://github.com/FriendsOfPHP/security-advisories/blob/master/typo3/cms/CVE-2021-21338.yaml
cvssv3.1 6.1 https://github.com/TYPO3/TYPO3.CMS/security/advisories/GHSA-4jhw-2p6j-5wmp
cvssv3.1_qr MODERATE https://github.com/TYPO3/TYPO3.CMS/security/advisories/GHSA-4jhw-2p6j-5wmp
generic_textual MODERATE https://github.com/TYPO3/TYPO3.CMS/security/advisories/GHSA-4jhw-2p6j-5wmp
cvssv3.1 6.1 https://nvd.nist.gov/vuln/detail/CVE-2021-21338
generic_textual MODERATE https://nvd.nist.gov/vuln/detail/CVE-2021-21338
cvssv3.1 6.1 https://packagist.org/packages/typo3/cms-core
generic_textual MODERATE https://packagist.org/packages/typo3/cms-core
cvssv3.1 6.1 https://typo3.org/security/advisory/typo3-core-sa-2021-001
generic_textual MODERATE https://typo3.org/security/advisory/typo3-core-sa-2021-001
Reference id Reference type URL
https://api.first.org/data/v1/epss?cve=CVE-2021-21338
https://github.com/FriendsOfPHP/security-advisories/blob/master/typo3/cms-core/CVE-2021-21338.yaml
https://github.com/FriendsOfPHP/security-advisories/blob/master/typo3/cms/CVE-2021-21338.yaml
https://github.com/TYPO3/TYPO3.CMS/security/advisories/GHSA-4jhw-2p6j-5wmp
https://nvd.nist.gov/vuln/detail/CVE-2021-21338
https://packagist.org/packages/typo3/cms-core
https://typo3.org/security/advisory/typo3-core-sa-2021-001
GHSA-4jhw-2p6j-5wmp https://github.com/advisories/GHSA-4jhw-2p6j-5wmp
No exploits are available.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Found at https://github.com/FriendsOfPHP/security-advisories/blob/master/typo3/cms-core/CVE-2021-21338.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:N/UI:R/S:C/C:L/I:L/A:N Found at https://github.com/FriendsOfPHP/security-advisories/blob/master/typo3/cms/CVE-2021-21338.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:N/UI:R/S:C/C:L/I:L/A:N Found at https://github.com/TYPO3/TYPO3.CMS/security/advisories/GHSA-4jhw-2p6j-5wmp
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:N/UI:R/S:C/C:L/I:L/A:N Found at https://nvd.nist.gov/vuln/detail/CVE-2021-21338
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:N/UI:R/S:C/C:L/I:L/A:N Found at https://packagist.org/packages/typo3/cms-core
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:N/UI:R/S:C/C:L/I:L/A:N Found at https://typo3.org/security/advisory/typo3-core-sa-2021-001
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 0.48529
EPSS Score 0.00253
Published At April 1, 2026, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2026-04-01T13:01:54.965973+00:00 GithubOSV Importer Import https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2021/03/GHSA-4jhw-2p6j-5wmp/GHSA-4jhw-2p6j-5wmp.json 38.0.0