Flatpak: flatpak: sandboxed app can signal unsandboxed processes in the same process group
Flatpak's process ID namespace separation does not prevent a sandboxed app's kill(0, signal) or killpg(0, signal) calls from reaching processes outside the sandbox that share the same process group. A malicious or compromised Flatpak app can use this to cause denial of service by terminating processes outside its sandbox, such as the desktop shell.
Flatpak: flatpak: arbitrary write in root context via path traversal in deploy directory files/etc
A path traversal vulnerability in Flatpak's handling of the files/etc directory during app deployment allows a malicious Flatpak app to cause certain host system files (such as passwd, group, machine-id, or resolv.conf) to be emptied or replaced with a symlink when the app is installed or upgraded. In system-wide installations, the write is performed as root.
Flatpak: flatpak: denial of service via unsanitized keys in exported desktop entry / d-bus service files
Flatpak passes through arbitrary vendor-extension keys unmodified when exporting an application's Desktop Entry (.desktop) and D-Bus Service (.service) files, instead of validating against an allowlist. A malicious Flatpak app can use this to cause denial of service (e.g. forced application restart loops) or to influence host D-Bus/systemd activation behavior beyond what the sandbox is intended to permit.
Flatpak: flatpak: world-writable temporary child repositories in system-helper cache path
Flatpak creates temporary child repository directories under the user cache with world-writable permissions (0777). On multi-user systems with a permissive umask, other local users could read or modify the temporary directory used while installing apps or runtimes, potentially causing installation failures (denial of service); tampered content would fail signature/digest verification rather than being trusted.
Flatpak: flatpak: world-readable oci authentication token in system-helper cache path
Flatpak writes the OCI repository authentication token with world-readable permissions (0644) in the system-helper's cache directory, allowing other local users on a multi-user system to read the token and impersonate the authenticated user against the OCI repository. Only OCI-based sources (e.g. as used by Fedora) are affected; libostree-based sources such as Flathub are not.
Flatpak: flatpak: arbitrary file deletion in root context via path traversal in deploy directory export/bin
A path traversal vulnerability in Flatpak's handling of the export/bin directory during app deployment allows a malicious Flatpak app to cause deletion of attacker-chosen files outside the deployment directory when the app is installed or upgraded. In system-wide installations, the deletion is performed as root.
A flaw was found in Flatpak. A Time-of-check to time-of-use (TOCTOU) race condition exists in the `org.freedesktop.Flatpak.SystemHelper` component. This vulnerability occurs because a privileged `chmod` operation executes before the OSTree repository validation within the `Deploy()` function. An attacker can exploit this timing window to redirect symlinks to arbitrary files, potentially leading to unauthorized file manipulation or information disclosure.
Flatpak metadata with ANSI control codes can cause misleading terminal output
Flatpak is a system for building, distributing, and running sandboxed desktop applications on Linux. In versions prior to 1.10.8, 1.12.8, 1.14.4, and 1.15.4, if an attacker publishes a Flatpak app with elevated permissions, they can hide those permissions from users of the `flatpak(1)` command-line interface by setting other permissions to crafted values that contain non-printable control characters such as `ESC`. A fix is available in versions 1.10.8, 1.12.8, 1.14.4, and 1.15.4. As a workaround, use a GUI like GNOME Software rather than the command-line interface, or only install apps whose maintainers you trust.
TIOCLINUX can send commands outside sandbox if running on a virtual console
Flatpak is a system for building, distributing, and running sandboxed desktop applications on Linux. Versions prior to 1.10.8, 1.12.8, 1.14.4, and 1.15.4 contain a vulnerability similar to CVE-2017-5226, but using the `TIOCLINUX` ioctl command instead of `TIOCSTI`. If a Flatpak app is run on a Linux virtual console such as `/dev/tty1`, it can copy text from the virtual console and paste it into the command buffer, from which the command might be run after the Flatpak app has exited. Ordinary graphical terminal emulators like xterm, gnome-terminal and Konsole are unaffected. This vulnerability is specific to the Linux virtual consoles `/dev/tt