In VOS and overly permissive "umask" may allow for authorized users of the server to gain unauthorized access through insecure file permiss…

published 2021-05-26 5 y ago modified 2026-06-17 4 mo ago also EUVD-2018-8305

cvss: 8.8; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 1.9%; EPSS 1.9% chance of exploitation in 30 days, percentile 80%
public exploits: 0; none known

In VOS and overly permissive "umask" may allow for authorized users of the server to gain unauthorized access through insecure file permissions that can result in an arbitrary read, write, or execution of newly created files and directories. Insecure umask setting was present throughout the Versa servers.

Patch / fix

fixed in 1

versa-networks versa_operating_system 16.1r2s11, 20.2.2, 21.1.1

Exploit prediction

1.92% chance of exploitation in the next 30 days, higher than 80% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
NVD	3.1	8.8	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD	2.0	6.5	AV:N/AC:L/Au:S/C:P/I:P/A:P

Affected products

n/a Versa VOS

Classification

Weakness

CWE-377 DEPRECATED: Insecure Temporary File
CWE-668 Exposure of Resource to Wrong Sphere

References

hackerone.com /reports/1168191
third-party-advisory

Sources

CVE List CVE-2018-16494
NVD CVE-2018-16494

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary