The mirror:// method implementation in Advanced Package Tool (APT) 1.6.x before 1.6.4 and 1.7.x before 1.7.0~alpha3 mishandles gpg signature verification for the InRelease file of a fallback mirror, aka mirrorfail.
| Software | From | Fixed in |
|---|---|---|
| canonical / ubuntu_linux | 18.04 | 18.04.x |
| debian / advanced_package_tool | 1.6.0 | 1.6.4 |
| debian / advanced_package_tool | 1.7.0-alpha | 1.7.0-alpha.x |
| debian / advanced_package_tool | 1.7.0-alpha1 | 1.7.0-alpha1.x |
| debian / advanced_package_tool | 1.7.0-alpha2 | 1.7.0-alpha2.x |