GHSA-j4rf-7357-f4cg · Severity: high · Ecosystem: go — Unpatched extfs vulnerabilities are exploitable through suid-mode Apptainer
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.
Conclusion & alert: CVE-2023-30549 is rated Low Risk (30.3/100): CVSS High severity, with low exploitation likelihood (EPSS 0.03%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2025-11-21 | 0.17% | 0.03% | -0.15% |
| 2 | 2025-11-18 | 0.03% | 0.17% | +0.14% |
| 3 | 2025-04-15 | — | 0.03% | — |
Full EPSS history (7 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 7.1 | 3.1 | HIGH |
|
2.5 | 4.0 | [email protected] |
| 7.8 | 3.1 | HIGH |
|
1.8 | 5.9 | [email protected] |
GHSA-j4rf-7357-f4cg · Severity: high · Ecosystem: go — Unpatched extfs vulnerabilities are exploitable through suid-mode Apptainer
| vendor | priority | summary | link |
|---|---|---|---|
alpine
|
high | CVE-2023-30549: 1 source package rows (apptainer); 9 state rows across 5 repos (3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 5, open 4. | https://security.alpinelinux.org/vuln/CVE-2023-30549 |
debian
|
unimportant | CVE-2023-30549 unimportant priority: Debian including 1 source packages (singularity-container), 1 status rows across 1 suites (sid): resolved 1. | https://security-tracker.debian.org/tracker/CVE-2023-30549 |
gentoo
|
high | CVE-2023-30549: 1 GLSA(s) (202311-13), 1 atom(s) (app-containers/apptainer); latest impact high. | https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2023-30549 |
ubuntu
|
medium | CVE-2023-30549 medium priority: Ubuntu including 1 source packages (singularity-container), 13 status rows across 13 suites (bionic, focal, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 5, ignored 4, needs-triage 4. | https://ubuntu.com/security/CVE-2023-30549 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| lfprojects | apptainer | < 1.1.8 | cpe:2.3:a:lfprojects:apptainer:*:*:*:*:*:go:*:* |
| sylabs | singularity | — | cpe:2.3:a:sylabs:singularity:*:*:*:*:*:*:*:* |
| redhat | enterprise_linux | 7.0 | cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:* |