Vulnerability · Published Apr 25, 2023 · Assigned by GitHub_M
CVE-2023-30549Unpatched extfs vulnerabilities are exploitable through suid-mode Apptainer
High 7.1
In plain English
A high-severity use-after-free in apptainer from apptainer. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 31% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.20 | apptainer | 1.1.8-r0 | ALPINE-CVE-2023-30549 |
| Alpine:v3.21 | apptainer | 1.1.8-r0 | ALPINE-CVE-2023-30549 |
| Alpine:v3.22 | apptainer | 1.1.8-r0 | ALPINE-CVE-2023-30549 |
| Alpine:v3.23 | apptainer | 1.1.8-r0 | ALPINE-CVE-2023-30549 |
| Alpine:v3.24 | apptainer | 1.1.8-r0 | ALPINE-CVE-2023-30549 |
| Go | github.com/apptainer/apptainer | 1.1.8 | GHSA-j4rf-7357-f4cg |
| Go | github.com/apptainer/apptainer | 1.1.8 | GO-2023-1738 |
| Ubuntu:25.10 | singularity-container | no fix listed | UBUNTU-CVE-2023-30549 |
| Ubuntu:26.04:LTS | singularity-container | no fix listed | UBUNTU-CVE-2023-30549 |
Affected products (as reported)
Weakness: CWE-416 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
References
- https://github.com/apptainer/apptainer/security/advisories/GHSA-j4rf-7357-f4cg x_refsource_CONFIRM
- https://github.com/apptainer/apptainer/commit/5a4964f5ba9c8d89a0e353b97f51fd607670a9f7 x_refsource_MISC
- https://github.com/torvalds/linux/commit/2220eaf90992c11d888fe771055d4de3303 x_refsource_MISC
- https://github.com/torvalds/linux/commit/4f04351888a83e595571de672e0a4a8b74f x_refsource_MISC
- https://access.redhat.com/security/cve/cve-2022-1184 x_refsource_MISC
- https://github.com/apptainer/apptainer/releases/tag/v1.1.8 x_refsource_MISC
- https://lwn.net/Articles/932136/ x_refsource_MISC
- https://lwn.net/Articles/932137/ x_refsource_MISC
- https://security-tracker.debian.org/tracker/CVE-2022-1184 x_refsource_MISC
- https://sylabs.io/2023/04/response-to-cve-2023-30549/ x_refsource_MISC
- https://ubuntu.com/security/CVE-2022-1184 x_refsource_MISC
- https://www.suse.com/security/cve/CVE-2022-1184.html x_refsource_MISC
- https://security.gentoo.org/glsa/202311-13