GHSA-xpv7-93cm-4mxv img_auth.php may leak private extension images into the public cache

• Packagist mediawiki/core: < 1.31.8 → fixed in 1.31.8 • Packagist mediawiki/core: >= 1.32.0, < 1.33.4 → fixed in 1.33.4 • Packagist mediawiki/core: >= 1.34.0, < 1.34.2 → fixed in 1.34.2

In MediaWiki before 1.31.8, 1.32.x and 1.33.x before 1.33.4, and 1.34.x before 1.34.2, private wikis behind a caching server using the img_auth.php image authorization security feature may have had their files cached publicly, so any unauthorized user could view them. This occurs because Cache-Control and Vary headers were mishandled.