Privilege escalation in Singularity

Published: 2020-09-25

Risk	Low
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2020-25039 CVE-2020-25040
CWE-ID	CWE-276
Exploitation vector	Local
Public exploit	N/A
Vulnerable software Subscribe	Singularity Universal components / Libraries / Libraries used by multiple products
Vendor	Singularity

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Incorrect default permissions

EUVDB-ID: #VU47113

Risk: Low

CVSSv3.1: 3.9 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-25039

CWE-ID: CWE-276 - Incorrect Default Permissions

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to incorrect default permissions on temporary directories used in fakeroot or user namespace container execution. A local user with access to the system can view contents of files and directories or modify them.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Singularity: 3.2.0 - 3.6.2

External links

http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00070.html
http://github.com/hpcng/singularity/security/advisories/GHSA-w6v2-qchm-grj7
http://medium.com/sylabs

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

2) Incorrect default permissions

EUVDB-ID: #VU47112