ghsa-7gcp-w6ww-2xv9
Vulnerability from github
Impact
Due to insecure handling of path traversal and the lack of path sanitization within unsquashfs (a distribution provided utility used by Singularity), it is possible to overwrite/create any files on the host filesystem during the extraction of a crafted squashfs filesystem.
Squashfs extraction occurs automatically for unprivileged execution of Singularity (either --without-suid installation or with allow setuid = no) when a user attempts to run an image which:
- is a local SIF image or a single file containing a squashfs filesystem
- is pulled from remote sources
library://orshub://
Image build is also impacted in a more serious way as it is often performed by the root user, allowing an attacker to overwrite/create files leading to a system compromise. Bootstrap methods library, shub and localimage trigger a squashfs extraction.
Patches
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.
Workarounds
There is no solid workaround except to temporarily avoid use of unprivileged mode with single file images, in favor of sandbox images instead. Regarding image build, temporarily avoid building from library and shub sources, and as much as possible use --fakeroot or a VM to limit potential impact.
For more information
General questions about the impact of the advisory / changes made in the 3.6.0 release can be asked in the:
Any sensitive security concerns should be directed to: security@sylabs.io
See our Security Policy here: https://sylabs.io/security-policy
{
"affected": [
{
"package": {
"ecosystem": "Go",
"name": "github.com/sylabs/singularity"
},
"ranges": [
{
"events": [
{
"introduced": "3.1.1"
},
{
"fixed": "3.6.4"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2020-15229"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": true,
"github_reviewed_at": "2021-05-21T22:17:06Z",
"nvd_published_at": "2020-10-14T19:15:00Z",
"severity": "HIGH"
},
"details": "### Impact\n\nDue to insecure handling of path traversal and the lack of path sanitization within `unsquashfs` (a distribution provided utility used by Singularity), it is possible to overwrite/create any files on the host filesystem during the extraction of a crafted squashfs filesystem.\n\nSquashfs extraction occurs automatically for unprivileged execution of Singularity (either `--without-suid` installation or with `allow setuid = no`) when a user attempts to run an image which:\n\n- is a local SIF image or a single file containing a squashfs filesystem\n- is pulled from remote sources `library://` or `shub://`\n\nImage build is also impacted in a more serious way as it is often performed by the root user, allowing an attacker to overwrite/create files leading to a system compromise. Bootstrap methods `library`, `shub` and `localimage` trigger a squashfs extraction.\n\n### Patches\n\nThis issue is addressed in Singularity 3.6.4.\n\nAll users are advised to upgrade to 3.6.4 especially if they use Singularity mainly for building image as root user.\n\n### Workarounds\n\nThere is no solid workaround except to temporarily avoid use of unprivileged mode with single file images, in favor of sandbox images instead. Regarding image build, temporarily avoid building from `library` and `shub` sources, and as much as possible use `--fakeroot` or a VM to limit potential impact.\n\n### For more information\n\nGeneral questions about the impact of the advisory / changes made in the 3.6.0 release can be asked in the:\n\n* [Singularity Slack Channel](https://bit.ly/2m0g3lX)\n* [Singularity Mailing List](https://groups.google.com/a/lbl.gov/forum/??sdf%7Csort:date#!forum/singularity)\n\nAny sensitive security concerns should be directed to: security@sylabs.io\n\nSee our Security Policy here: https://sylabs.io/security-policy",
"id": "GHSA-7gcp-w6ww-2xv9",
"modified": "2021-05-21T22:17:06Z",
"published": "2021-05-24T16:59:53Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/hpcng/singularity/security/advisories/GHSA-7gcp-w6ww-2xv9"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2020-15229"
},
{
"type": "WEB",
"url": "https://github.com/hpcng/singularity/pull/5611"
},
{
"type": "WEB",
"url": "https://github.com/hpcng/singularity/commit/eba3dea260b117198fdb6faf41f2482ab2f8d53e"
},
{
"type": "WEB",
"url": "https://github.com/hpcng/singularity/blob/v3.6.4/CHANGELOG.md#security-related-fixes"
},
{
"type": "WEB",
"url": "http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00070.html"
},
{
"type": "WEB",
"url": "http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00071.html"
},
{
"type": "WEB",
"url": "http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00009.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:N",
"type": "CVSS_V3"
}
],
"summary": "Path traversal and files overwrite with unsquashfs in singularity"
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.