A use-after-free flaw was found in PackageKitd. In some conditions, the order of cleanup mechanics for a transaction could be impacted. As a result, some memory access could occur on memory regions that were previously freed. Once freed, a memory region can be reused for other allocations and any previously stored data in this memory region is considered lost.
PackageKit provided detailed error messages to unprivileged callers that exposed information about file presence and mimetype of files that the user would be unable to determine on its own.
PackageKit's apt backend mistakenly treated all local debs as trusted. The apt security model is based on repository trust and not on the contents of individual files. On sites with configured PolicyKit rules this may allow users to install malicious packages.