Path Traversal in Hpcng Singularity
CVE-2020-15229
Singularity (an open source container platform) from version 3.1.1 through 3.6.3 has a vulnerability. Due to insecure handling of path traversal and the lack of path sanitization within `unsquashfs`, it is possible to overwrite/create any files on the host filesystem during the extraction with a crafted squashfs filesystem. The extraction occurs automatically for unprivileged (either installation or with `allow setuid = no`) run of Singularity when a user attempt to run an image which is a local SIF image or a single file containing a squashfs filesystem and is coming from remote sources `library://` or `shub://`. Image build is also impacted in a more serious way as it can be used by a root user, allowing an attacker to overwrite/create files leading to a system compromise, so far bootstrap methods `library`, `shub` and `localimage` are triggering the squashfs extraction. This issue is addressed in Singularity 3.6.4. All users are advised to upgrade to 3.6.4 especially if they use Singularity mainly for building image as root user. There is no solid workaround except to temporary avoid to use unprivileged mode with single file images in favor of sandbox images instead. Regarding image build, temporary avoid to build from `library` and `shub` sources and as much as possible use `--fakeroot` or a VM for that.
Vulnerability class: Path Traversal (Directory Traversal)
EPSS: 0.020 (79.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:N.
Affected products
- Hpcng Singularity — versions < 3.6.4
- Sylabs Singularity
- Opensuse Backports_sle — versions 15.0
- Opensuse Leap — versions 15.1, 15.2
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security-advisories@github.com (x_refsource_CONFIRM, Third Party Advisory)
- security-advisories@github.com (Third Party Advisory, x_refsource_MISC, Release Notes)
- security-advisories@github.com (Patch, Third Party Advisory, x_refsource_MISC)
- security-advisories@github.com (Patch, Third Party Advisory, x_refsource_MISC)
- security-advisories@github.com (vendor-advisory, Mailing List, Third Party Advisory, Broken Link, x_refsource_SUSE)
- security-advisories@github.com (vendor-advisory, Mailing List, Third Party Advisory, Broken Link, x_refsource_SUSE)
- security-advisories@github.com (vendor-advisory, Mailing List, Third Party Advisory, Broken Link, x_refsource_SUSE)
Frequently asked questions
- What is CVE-2020-15229?
- CVE-2020-15229 is a high-severity vulnerability in Hpcng Singularity, classified under Path Traversal. CVSS score: 8.2/10. Published 2020-10-14.
- How severe is CVE-2020-15229?
- High severity. CVSS v3 base score is 8.2 out of 10.
- Is CVE-2020-15229 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.