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->cachedtransactionflags 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->cachedtransactionflags 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): pktransactionsetstate() silently discards backward state transitions (e.g. RUNNING → WAITINGFORAUTH) 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 cachedtransactionflags at dispatch time, not at authorization time. If flags were overwritten between authorization and execution, the backend sees the attacker's flags.

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 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.