CVE-2020-25039: Github.com/sylabs/singularity Insecure Permissions On User Namespace Vulnerability
HIGHCVE-2020-25039 is a HIGH (CVSS 8.1) insecure permissions on user namespace vulnerability (CWE-668: Exposure of Resource to Wrong Sphere) affecting Github.com/sylabs/singularity libraries in the Go ecosystem. The issue involves insecure permissions on user namespace / fakeroot temporary rootfs in singularity. Remediation is available by upgrading affected packages to version 3.6.3.
CVE-2020-25039 at a Glance
Security Impact
CVSS: 8.1
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N).
How to Fix CVE-2020-25039
To remediate this vulnerability, upgrade all affected Github.com/sylabs/singularity dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
Upgrade github.com/sylabs/singularity to 3.6.3Run the following command in your project directory to verify that all resolved dependencies use the patched release:
inspect dependencies for github.com/sylabs/singularityHow to Check if You Are Affected
To determine whether your application is affected by CVE-2020-25039, inspect your project dependencies for Github.com/sylabs/singularity:
inspect dependencies for github.com/sylabs/singularityAnalyze the terminal output to locate any version of Github.com/sylabs/singularity in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 3.6.3), your application is affected.
Note: Verify declared build manifests and deployed runtime container environments.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-668: Exposure of Resource to Wrong Sphere, where the product exposes a resource to the wrong control sphere, providing unintended actors with inappropriate access to the resource. In Github.com/sylabs/singularity, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2020-25039 Affected Github.com/sylabs/singularity Versions
1 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
github.com/sylabs/singularity
|
Go |
≥ 3.2.0
< 3.6.3
|
3.6.3
|
References
Frequently Asked Questions
What is CVE-2020-25039?
Which Github.com/sylabs/singularity versions are affected?
What version fixes CVE-2020-25039?
Is github.com/sylabs/singularity affected?
What is the CVSS score of CVE-2020-25039?
What CWE is associated with CVE-2020-25039?
How can I check Go dependencies for CVE-2020-25039?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-w6v2-qchm-grj7",
"modified" : "2021-05-24T17:12:01Z",
"published" : "2021-12-20T18:25:46Z",
"aliases" : [ "CVE-2020-25039" ],
"summary" : "Insecure permissions on user namespace / fakeroot temporary rootfs in Singularity",
"details" : "### Impact\n\nInsecure permissions on temporary directories used in fakeroot or user namespace container execution.\n\nWhen a Singularity action command (run, shell, exec) is run with the fakeroot or user namespace option, Singularity will extract a container image to a temporary sandbox directory. Due to insecure permissions on the temporary directory it is possible for any user with access to the system to read the contents of the image. Additionally, if the image contains a world-writable file or directory, it is possible for a user to inject arbitrary content into the running container.\n\n### Patches\n\nThis issue is addressed in Singularity 3.6.3.\n\nAll users are advised to upgrade to 3.6.3.\n\n### Workarounds\n\nThe issue is mitigated if `TMPDIR` is set to a location that is only accessible to the user, as any subdirectories directly under `TMPDIR` cannot then be accessed by others. However, this is difficult to enforce so it is not recommended to rely on this as a mitigation.\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",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "Go",
"name" : "github.com/sylabs/singularity"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "3.2.0"
}, {
"fixed" : "3.6.3"
} ]
} ]
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/hpcng/singularity/security/advisories/GHSA-w6v2-qchm-grj7"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-25039"
}, {
"type" : "WEB",
"url" : "https://medium.com/sylabs"
}, {
"type" : "WEB",
"url" : "http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00070.html"
}, {
"type" : "WEB",
"url" : "http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00088.html"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-668", "CWE-732" ],
"severity" : "HIGH",
"github_reviewed" : true,
"github_reviewed_at" : "2021-05-24T17:12:01Z",
"nvd_published_at" : "2020-09-16T18:15:00Z"
}
}