Bug 889284 (CVE-2022-47952)

Summary:	<app-containers/lxc-5.0.2: file existence disclosure
Product:	Gentoo Security	Reporter:	John Helmert III <ajak>
Component:	Vulnerabilities	Assignee:	Gentoo Security <security>
Status:	IN_PROGRESS ---
Severity:	minor	CC:	juippis, virtualization
Priority:	Normal
Version:	unspecified
Hardware:	All
OS:	Linux
URL:	https://github.com/MaherAzzouzi/CVE-2022-47952
Whiteboard:	B4 [glsa?]
Package list:		Runtime testing required:	---

Description John Helmert III archtester

2023-01-01 15:54:05 UTC

CVE-2022-47952 (https://github.com/lxc/lxc/blob/0b83d71c2c8f3bac9503f894cd84584f79258bb3/lxc.spec.in#L274):
https://github.com/lxc/lxc/blob/0b83d71c2c8f3bac9503f894cd84584f79258bb3/src/lxc/cmd/lxc_user_nic.c#L1085-L1104
https://bugs.launchpad.net/ubuntu/+source/lxc/+bug/1783591/comments/45

lxc-user-nic in lxc through 5.0.1 is installed setuid root, and may allow local users to infer whether any file exists, even within a protected directory tree, because "Failed to open" often indicates that a file does not exist, whereas "does not refer to a network namespace path" often indicates that a file exists. NOTE: this is different from CVE-2018-6556 because the CVE-2018-6556 fix design was based on the premise that "we will report back to the user that the open() failed but the user has no way of knowing why it failed"; however, in many realistic cases, there are no plausible reasons for failing except that the file does not exist.

As usual with this character, there's no reference to an upstream
report.

Comment 1 John Helmert III archtester

2023-01-01 20:25:56 UTC

The guy apparently made a PR upstream, copy-pasting the CVE description: https://github.com/lxc/lxc/pull/4245

I doubt upstream will find this desirable, seeing as he's only commented out some output functions and hasn't tried to fix the CI issues.

Comment 2 Joonas Niilola gentoo-dev

2023-01-21 13:50:45 UTC

https://discuss.linuxcontainers.org/t/lxc-5-0-2-lts-has-been-released/16210

https://gitweb.gentoo.org/repo/gentoo.git/commit/app-containers/lxc?id=c2c4be8ee254b45ac05633a14fec9cff88c21ce9

Comment 3 John Helmert III archtester

2023-01-23 03:54:41 UTC

Thanks, please stabilize when ready.

Comment 4 Hans de Graaff gentoo-dev

2023-10-14 07:47:29 UTC

commit f565998a51b1e190e4595d726873e1775b2bc4c8
Author: Joonas Niilola <juippis@gentoo.org>
Date:   Wed Feb 22 09:11:49 2023 +0200

    app-containers/lxc: drop 5.0.1-r2