A sandbox information disclosure exists in Twig before 1.38.0 and 2.x before 2.7.0 because, under some circumstances, it is possible to call the __toString() method on an object even if not allowed by the security policy in place.
References
- https://nvd.nist.gov/vuln/detail/CVE-2019-9942
- https://github.com/twigphp/Twig/commit/eac5422956e1dcca89a3669a03a3ff32f0502077
- https://github.com/FriendsOfPHP/security-advisories/blob/master/twig/twig/CVE-2019-9942.yaml
- https://seclists.org/bugtraq/2019/Mar/60
- https://symfony.com/blog/twig-sandbox-information-disclosure
- https://www.debian.org/security/2019/dsa-4419
- https://github.com/advisories/GHSA-vxrc-68xx-x48g