The blocks in the sales_order_print.xml layout in the Magento_Sales module had never been set to private or non-cacheable. Therefore, if the full-page cache had enabled, and a signed-in user visits the print order page. Any other signed in user could visit that url and see their detailed order information.
Part of update Magento 2.2.6 and 2.1.15 Security Update
This vulnerability affects the following application versions:
- Magento 2.0.0
- Magento 2.0.0-rc
- Magento 2.0.0-rc2
- Magento 2.0.1
- Magento 2.0.2
- Magento 2.0.3
- Magento 2.0.4
- Magento 2.0.5
- Magento 2.0.6
- Magento 2.0.7
- Magento 2.0.8
- Magento 2.0.9
- Magento 2.0.10
- Magento 2.0.11
- Magento 2.0.12
- Magento 2.0.13
- Magento 2.0.14
- Magento 2.0.15
- Magento 2.0.16
- Magento 2.0.17
- Magento 2.0.18
- Magento 2.1.0
- Magento 2.1.0-rc1
- Magento 2.1.0-rc2
- Magento 2.1.0-rc3
- Magento 2.1.1
- Magento 2.1.2
- Magento 2.1.3
- Magento 2.1.4
- Magento 2.1.5
- Magento 2.1.6
- Magento 2.1.7
- Magento 2.1.8
- Magento 2.1.9
- Magento 2.1.10
- Magento 2.1.11
- Magento 2.1.12
- Magento 2.1.13
- Magento 2.1.14
- Magento 2.2.0
- Magento 2.2.0-rc2.0
- Magento 2.2.0-rc2.1
- Magento 2.2.0-rc2.2
- Magento 2.2.0-rc2.3
- Magento 2.2.0-rc3.0
- Magento 2.2.0-RC1.1
- Magento 2.2.0-RC1.2
- Magento 2.2.0-RC1.3
- Magento 2.2.0-RC1.4
- Magento 2.2.0-RC1.5
- Magento 2.2.0-RC1.6
- Magento 2.2.0-RC1.8
- Magento 2.2.1
- Magento 2.2.2
- Magento 2.2.3
- Magento 2.2.4
- Magento 2.2.5