flatpak: CVE-2023-28101: escape characters in metadata can hide permissions changes

Debian Bug report logs - #1033098
flatpak: CVE-2023-28101: escape characters in metadata can hide permissions changes

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Message #5 received at submit@bugs.debian.org (full text, mbox, reply):

From: Simon McVittie <smcv@debian.org>

To: Debian Bug Tracking System <submit@bugs.debian.org>

Subject: flatpak: CVE-2023-28101: escape characters in metadata can hide permissions changes

Date: Fri, 17 Mar 2023 09:38:35 +0000

Package: flatpak
Version: 0.6.0-1
Severity: serious
Tags: security pending fixed-upstream
X-Debbugs-Cc: Debian Security Team <team@security.debian.org>
Forwarded: https://github.com/flatpak/flatpak/security/advisories/GHSA-h43h-fwqx-mpp8
Control: fixed -1 1.14.4-1
Control: fixed -1 1.15.4-1

When installing or upgrading a Flatpak app using the flatpak(1) CLI,
the user is normally shown any special permissions that the new app has
in its metadata, so that they can make a somewhat informed choice about
whether to allow its installation.

Ryan Gonzalez discovered that malicious Flatpak app maintainers could
manipulate or hide this display of permissions by requesting permissions
that include ANSI terminal control codes or other non-printable characters.
This was fixed in Flatpak 1.14.4, 1.15.4, 1.12.8 and 1.10.8 by displaying
non-printable characters in an escaped format (\xXX, \uXXXX, \UXXXXXXXX)
so that they do not alter the terminal's behaviour, and also by treating
non-printable characters in certain contexts as invalid (not allowed).

Graphical frontends for libflatpak, like GNOME Software and KDE Plasma
Discover, are not directly affected by this. When retrieving an app's
permissions to show to the user, the graphical frontend continues to be
responsible for filtering or escaping any characters that would have a
special meaning for its GUI libraries.

I've already contacted the security team asking for permission to upload
1.10.8 as a security update for bullseye.

    smcv

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