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NVD / CVE Program· CNA GitHub_M

CVE-2023-30549: Unpatched extfs vulnerabilities are exploitable through suid-mode Apptainer

Noroxi assessment

Priority: Monitor (action score 31/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.36% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: apptainer (Alpine:v3.19) 1.1.8-r0; github.com/apptainer/apptainer (Go) 1.1.8; apptainer (openSUSE:Leap 15.5) 1.3.0-bp155.3.3.2.

Low priority for now. Upgrade to apptainer (Alpine:v3.19) 1.1.8-r0; github.com/apptainer/apptainer (Go) 1.1.8; apptainer (openSUSE:Leap 15.5) 1.3.0-bp155.3.3.2 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Apr 25, 2023
Updated
Oct 23, 2026
EPSS
0.3% · 30th percentile

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.3%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
7.8
CNA · GitHub_M
7.1
0.7 point gap

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2023-30549

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
lfprojectsapptainer
sylabssingularity
redhatenterprise linux

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • lfprojects apptainerbefore 1.1.8
  • redhat enterprise linux7.0
  • sylabs singularityall versions

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • apptainer apptainer

    • < 1.1.8affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Alpine:v3.19apptainerbefore 1.1.8-r01.1.8-r0
Gogithub.com/apptainer/apptainerbefore 1.1.81.1.8
openSUSE:Leap 15.5apptainerbefore 1.3.0-bp155.3.3.21.3.0-bp155.3.3.2
openSUSE:Leap 15.5squashfusebefore 0.5.0-bp155.2.10.5.0-bp155.2.1
openSUSE:Tumbleweedapptainerbefore 1.1.8-1.11.1.8-1.1
SUSE:Package Hub 15 SP5apptainerbefore 1.3.0-bp155.3.3.21.3.0-bp155.3.3.2
SUSE:Package Hub 15 SP5squashfusebefore 0.5.0-bp155.2.10.5.0-bp155.2.1

Same product

lfprojects: all records

Other highest-scoring records for the same primary product.

  • CVE-2025-65105Apptainer ineffective application of selinux and apparmor --security options
    21Monitor
  • CVE-2023-38496Apptainer's ineffective privileges drop when requesting container network
    13Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
alpine:apptainer1.1.8-r0 · Alpine:v3.19Package registry (OSV)
Go:github.com/apptainer/apptainer1.1.8Package registry (OSV)
opensuse:apptainer1.3.0-bp155.3.3.2 · openSUSE:Leap 15.5Package registry (OSV)
opensuse:squashfuse0.5.0-bp155.2.1 · openSUSE:Leap 15.5Package registry (OSV)
suse:apptainer1.3.0-bp155.3.3.2 · SUSE:Package Hub 15 SP5Package registry (OSV)
suse:squashfuse0.5.0-bp155.2.1 · SUSE:Package Hub 15 SP5Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

nvd-primary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

c
free(dev->buf);/* ... another thread is still running ... */process(dev->buf);

Fixed

c
lock(&dev->lock);free(dev->buf);dev->buf = NULL;unlock(&dev->lock);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (12 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records