GLSA-202311-13 : Apptainer: Privilege Escalation

high Nessus Plugin ID 186267

Description

The remote host is affected by the vulnerability described in GLSA-202311-13 (Apptainer: Privilege Escalation)

- Apptainer is an open source container platform for Linux. There is an ext4 use-after-free flaw that is exploitable through versions of Apptainer < 1.1.0 and installations that include apptainer-suid < 1.1.8 on older operating systems where that CVE has not been patched. That includes Red Hat Enterprise Linux 7, Debian 10 buster (unless the linux-5.10 package is installed), Ubuntu 18.04 bionic and Ubuntu 20.04 focal.
Use-after-free flaws in the kernel can be used to attack the kernel for denial of service and potentially for privilege escalation. Apptainer 1.1.8 includes a patch that by default disables mounting of extfs filesystem types in setuid-root mode, while continuing to allow mounting of extfs filesystems in non- setuid rootless mode using fuse2fs. Some workarounds are possible. Either do not install apptainer-suid (for versions 1.1.0 through 1.1.7) or set `allow setuid = no` in apptainer.conf. This requires having unprivileged user namespaces enabled and except for apptainer 1.1.x versions will disallow mounting of sif files, extfs files, and squashfs files in addition to other, less significant impacts. (Encrypted sif files are also not supported unprivileged in apptainer 1.1.x.). Alternatively, use the `limit containers` options in apptainer.conf/singularity.conf to limit sif files to trusted users, groups, and/or paths, and set `allow container extfs = no` to disallow mounting of extfs overlay files. The latter option by itself does not disallow mounting of extfs overlay partitions inside SIF files, so that's why the former options are also needed. (CVE-2023-30549)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

All Apptainer users should upgrade to the latest version:

# emerge --sync # emerge --ask --oneshot --verbose >=app-containers/apptainer-1.1.8

See Also

https://security.gentoo.org/glsa/202311-13

https://bugs.gentoo.org/show_bug.cgi?id=905091

Plugin Details

Severity: High

ID: 186267

File Name: gentoo_GLSA-202311-13.nasl

Version: 1.2

Type: local

Published: 11/25/2023

Updated: 12/21/2023

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5

Vector: CVSS2#AV:L/AC:L/Au:S/C:C/I:C/A:C

CVSS Score Source: CVE-2023-30549

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 6.8

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:gentoo:linux:apptainer, cpe:/o:gentoo:linux

Required KB Items: Host/local_checks_enabled, Host/Gentoo/release, Host/Gentoo/qpkg-list

Exploit Ease: No known exploits are available

Patch Publication Date: 11/25/2023

Vulnerability Publication Date: 4/25/2023

Reference Information

CVE: CVE-2023-30549