Vulnerability identifier: #VU13830

Vulnerability risk: Medium

CVSSv3.1: 5.8 [CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: N/A

CWE-ID: CWE-502

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
TYPO3
Web applications / CMS

Vendor: TYPO3

Description

The vulnerability allows a remote authenticated user to compromise vulnerable system.

The vulnerability exists due to improper sanitization of user-supplied data in the Form Framework (system extension "form") when being used with the additional PHP PECL package “yaml”. A privileged attacker can upload a specially crafted form template and execute arbitrary PHP code on the server.

Successful exploitation of the vulnerability requires that setting "yaml.decode_php" option is enabled.

Mitigation
Update to  version 8.7.17 or 9.3.1.

Vulnerable software versions

TYPO3: 9.0.0 - 9.3.0, 8.0.0 - 8.7.16

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External links
http://typo3.org/security/advisory/typo3-core-sa-2018-004/

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated privileged user via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.