In TYPO3 CMS greater than or equal to 9.0.0 and less than 9.5.20, and greater than or equal to 10.0.0 and less than 10.4.6, it has been discovered that an internal verification mechanism can be used to generate arbitrary checksums. This allows to inject arbitrary data having a valid cryptographic message authentication code (HMAC-SHA1) and can lead to various attack chains including potential privilege escalation, insecure deserialization & remote code execution. The overall severity of this vulnerability is high based on mentioned attack chains and the requirement of having a valid backend user session (authenticated). This has been patched in versions 9.5.20 and 10.4.6.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - In TYPO3 CMS greater than or equal to 9.0.0 and less than 9.5.20, and greater than or equal to 10.0.0 and
    less than 10.4.6, it has been discovered that an internal verification mechanism can be used to generate
    arbitrary checksums. This allows to inject arbitrary data having a valid cryptographic message
    authentication code (HMAC-SHA1) and can lead to various attack chains including potential privilege
    escalation, insecure deserialization & remote code execution. The overall severity of this vulnerability
    is high based on mentioned attack chains and the requirement of having a valid backend user session
    (authenticated). This has been patched in versions 9.5.20 and 10.4.6. (CVE-2020-15098)

Typo3 Team reports :

In case an attacker manages to generate a valid cryptographic message authentication code (HMAC-SHA1) - either by using a different existing vulnerability or in case the internal encryptionKey was exposed - it is possible to retrieve arbitrary files of a TYPO3 installation. This includes the possibility to fetch typo3conf/LocalConfiguration.php which again contains the encryptionKey as well as credentials of the database management system being used. In case a database server is directly accessible either via internet or in a shared hosting network, this allows to completely retrieve, manipulate or delete database contents. This includes creating an administration user account - which can be used to trigger remote code execution by injecting custom extensions.

It has been discovered that an internal verification mechanism can be used to generate arbitrary checksums. This allows to inject arbitrary data having a valid cryptographic message authentication code (HMAC-SHA1) and can lead to various attack chains as described below.

ID	Name	Product	Family	Severity
416759	SCA: security update for typo3/cms, typo3/cms-core (GHSA-m5vr-3m74-jwxp)	Tenable Cloud Security	SCA Checks	high
416759	SCA: security update for typo3/cms, typo3/cms-core (GHSA-m5vr-3m74-jwxp)	Tenable Self-Hosted Container Security	SCA Checks	high
139349	FreeBSD : typo3 -- multiple vulnerabilities (eab964f8-d632-11ea-9172-4c72b94353b5)	Nessus	FreeBSD Local Security Checks	high

Detections

Analytics

CVE-2020-15098

high

Tenable Plugins

high

high

high