Drupal 8.4.x versions before 8.4.5 and Drupal 7.x versions before 7.57 has
a Drupal.checkPlain() JavaScript function which is used to escape
potentially dangerous text before outputting it to HTML (as JavaScript
output does not typically go through Twig autoescaping). This function does
not correctly handle all methods of injecting malicious HTML, leading to a
cross-site scripting vulnerability under certain circumstances. The PHP
functions which Drupal provides for HTML escaping are not affected.
Upstream:released (7.57-1)
Ubuntu 12.04 ESM (Precise Pangolin):DNE
Ubuntu 14.04 ESM (Trusty Tahr):DNE (trusty was needed)
Ubuntu 16.04 LTS (Xenial Xerus):needed
Ubuntu 18.04 LTS (Bionic Beaver):DNE
Ubuntu 20.04 LTS (Focal Fossa):DNE
Ubuntu 20.10 (Groovy Gorilla):DNE
More Information

Updated: 2020-09-09 21:36:01 UTC (commit b67d7d8b03f173f825cd706df5bd078bca500b0e)