CVE-2020-15098: Missing Required Cryptographic Step Leading to Sensitive Information Disclosure in TYPO3 CMS
### Meta CVSS: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C (8.2) CWE-325, CWE-20, CWE-200, CWE-502
Problem 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.
TYPO3-CORE-SA-2020-007, CVE-2020-15099: Potential Privilege Escalation + the database server used for a TYPO3 installation must be accessible for an attacker (either via internet or shared hosting network) + CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C (7.5, high) TYPO3-CORE-SA-2016-013, CVE-2016-5091: Insecure Deserialization & Remote Code Execution + an attacker must have access to at least one Extbase plugin or module action in a TYPO3 installation + CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C (9.1, critical)
The overall severity of this vulnerability is high (8.2) based on mentioned attack chains and the requirement of having a valid backend user session (authenticated).
Solution Update to TYPO3 versions 9.5.20 or 10.4.6 that fix the problem described.
Credits Thanks to TYPO3 security team member Oliver Hader who reported and fixed the issue.
References TYPO3-CORE-SA-2020-008
Other sources
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.
TYPO3-CORE-SA-2020-008: Sensitive Information Disclosure
Affected Software
Event History
Frequently Asked Questions
What is CVE-2020-15098?
CVE-2020-15098 is a vulnerability in TYPO3 CMS that allows sensitive information disclosure.
What is the severity of CVE-2020-15098?
The severity of CVE-2020-15098 is high, with a CVSS score of 8.8.
Which versions of TYPO3 CMS are affected by CVE-2020-15098?
TYPO3 CMS versions 9.0.0 to 9.5.20 and versions 10.0.0 to 10.4.6 are affected by CVE-2020-15098.
How can this vulnerability be exploited?
This vulnerability can be exploited by using an internal verification mechanism to generate arbitrary checksums and inject arbitrary data.
How can I fix CVE-2020-15098?
To fix CVE-2020-15098, it is recommended to upgrade TYPO3 CMS to version 9.5.20 or 10.4.6, depending on the installed version.