Both the jessie release notes [1] and the draft stretch release notes [2] contain the following text:
5.2.1. Security status of web browsers Debian 9 includes several browser engines which are affected by a steady stream of security vulnerabilities. The high rate of vulnerabilities and partial lack of upstream support in the form of long term branches make it very difficult to support these browsers with backported security fixes. Additionally, library interdependencies make it impossible to update to newer upstream releases. Therefore, browsers built upon the webkit, qtwebkit and khtml engines are included in Stretch, but not covered by security support. These browsers should not be used against untrusted websites. For general web browser use we recommend Firefox or Chromium. Chromium - while built upon the Webkit codebase - is a leaf package, which will be kept up-to-date by rebuilding the current Chromium releases for stable. Firefox and Thunderbird will also be kept up-to-date by rebuilding the current ESR releases for stable. Note how from the headline to the sugested mitigation everything talks about web *browsers*. Web browsers other than Firefox or Chromium are rarely used and the recommendation to use only one of these two is not a big issue in practice. Other uses of browser engines are the real problem, for example: 1. Which email client is part of the default Debian desktop? 2. Which browser engine does this email client use to render HTML emails? 3. How many CVEs are known to affect the version of this browser engine in jessie? As far as I know, the answers are: 1. Evolution 2. WebKitGTK+ 3. around 100 For making the limits of security support less hidden, I would suggest the following: 1. Handle packages without security support better in buster It is too late for stretch, but for buster the situation should be improved. Installing Debian should avoid installing any software without security support. Does it make sense to ship software without security support in stable releases or would it be better to remove such software? 2. Fix the release notes The release notes should stop hiding the problem by not mentioning the worst parts of the problem I am not good at marketing-speech to make contents like After installing Debian, it is strongly recommended to remove all software that is not security-supported. not sound like a complete embarrassment, someone who is better at that should suggest a wording. 3. Use Breaks in debian-security-support It is already recommended in the release notes to install the debian-security-support package, but that does not make it very visible when you are about to install packages without security support. If debian-security-support has Breaks on all packages without full security support, then package managers like apt will automatically give information like "installing debian-security-support would remove the following packages:" or "installing this package will remove debian-security-support". cu Adrian [1] http://www.debian.org/releases/stable/amd64/release-notes/ch-information.en.html#browser-security [2] https://www.debian.org/releases/stretch/amd64/release-notes/ch-information.en.html#browser-security -- "Is there not promise of rain?" Ling Tan asked suddenly out of the darkness. There had been need of rain for many days. "Only a promise," Lao Er said. Pearl S. Buck - Dragon Seed