Cross-Site Scripting in ternary conditional operator
> ### Meta
> * CVSS: `CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N/E:F/RL:O/RC:C`(5.0)
> * CWE-79
---
:information_source: This vulnerability has been fixed in May 2019 already, CVE and GHSA were assigned later in October 2020
---
### Problem
It has been discovered that the Fluid Engine (package `typo3fluid/fluid`) is vulnerable to cross-site scripting when making use of the ternary conditional operator in templates like the following.
```
{showFullName ? fullName : defaultValue}
```
### Solution
Update to versions 2.0.5, 2.1.4, 2.2.1, 2.3.5, 2.4.1, 2.5.5 or 2.6.1 of this `typo3fluid/fluid` package that fix the problem described.
Updated versions of this package are bundled in following TYPO3 (`typo3/cms-core`) releases:
* TYPO3 v8.7.25 (using `typo3fluid/fluid` v2.5.5)
* TYPO3 v9.5.6 (using `typo3fluid/fluid` v2.6.1)
### Credits
Thanks to Bill Dagou who reported this issue and to TYPO3 core merger Claus Due who fixed the issue.
### References
* TYPO3-CORE-SA-2019-013
https://typo3.org/security/advisory/typo3-core-sa-2019-013