Advisory Weakness Curation

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 https://typo3.org/security/advisory/typo3-core-sa-2020-007, CVE-2020-15099 https://nvd.nist.gov/vuln/detail/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 https://typo3.org/security/advisory/typo3-core-sa-2016-013, CVE-2016-5091 https://nvd.nist.gov/vuln/detail/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 https://typo3.org/security/advisory/typo3-core-sa-2020-008

Use of a Broken or Risky Cryptographic Algorithm 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.

Deserialization of Untrusted Data In TYPO3 CMS, 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).