PackageKit is a a D-Bus abstraction layer that allows the user to manage packages in a secure way using a cross-distro, cross-architecture API. PackageKit between and including versions 1.0.2 and 1.3.4 is vulnerable to a time-of-check time-of-use (TOCTOU) race condition on transaction flags that allows unprivileged users to install packages as root and thus leads to a local privilege escalation. This is patched in version 1.3.5. A local unprivileged user can install arbitrary RPM packages as root, including executing RPM scriptlets, without authentication. The vulnerability is a TOCTOU race condition on `transaction->cached_transaction_flags` combined with a silent state-machine guard that discards illegal backward transitions while leaving corrupted flags in place. Three bugs exist in `src/pk-transaction.c`: 1. Unconditional flag overwrite (line 4036): `InstallFiles()` writes caller-supplied flags to `transaction->cached_transaction_flags` without checking whether the transaction has already been authorized/started. A second call blindly overwrites the flags even while the transaction is RUNNING. 2. Silent state-transition rejection (lines 873–882): `pk_transaction_set_state()` silently discards backward state transitions (e.g. `RUNNING` → `WAITING_FOR_AUTH`) but the flag overwrite at step 1 already happened. The transaction continues running with corrupted flags. 3. Late flag read at execution time (lines 2273–2277): The scheduler's idle callback reads cached_transaction_flags at dispatch time, not at authorization time. If flags were overwritten between authorization and execution, the backend sees the attacker's flags.

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.

A flaw was found in PackageKit in the way some of the methods exposed by the Transaction interface examines files. This issue allows a local user to measure the time the methods take to execute and know whether a file owned by root or other users exists.

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.

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 0.6.17 allows installation of unsigned RPM packages as though they were signed which may allow installation of non-trusted packages and execution of arbitrary code.

An authentication bypass flaw has been found in PackageKit before 1.1.10 that allows users without administrator privileges to install signed packages. A local attacker can use this vulnerability to install vulnerable packages to further compromise a system.

The Zypper (aka zypp) backend in PackageKit before 0.8.8 allows local users to downgrade packages via the "install updates" method.