CVE-2018-16494Network attack vector

Authenticated file access via overly permissive umask

Published May 26, 2021 · Updated Aug 5, 2024

Improper file permissions in Versa Networks Versa Operating System allow remote authenticated users to read, write, or execute newly created files. Server-wide process creation uses an overly permissive umask, causing new files and directories to receive permissions that expose them beyond their intended owners. An authorized server account is required, after which affected objects can disclose data, accept unauthorized modification, or run attacker-controlled content.

CVSS severity8.8
High
EPSS probability1.92%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper file permissions in Versa Networks Versa Operating System allow remote authenticated users to read, write, or execute newly created files. Server-wide process creation uses an overly permissive umask, causing new files and directories to receive permissions that expose them beyond their intended owners. An authorized server account is required, after which affected objects can disclose data, accept unauthorized modification, or run attacker-controlled content.

The record

CVE
CVE-2018-16494
Published
May 26, 2021
Updated
Aug 5, 2024
Vendor
Versa Networks
Product
Versa Operating System (VOS)
Classifications
CWE-377, CWE-668, T1005
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 26, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Fixed Versions: 16.1R2S11, 20.2.2, 21.1.1, 21.2.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Versa Networks · Versa Operating System (VOS)version=Fixed Versions: 16.1R2S11, 20.2.2, 21.1.1, 21.2.1

Published CVSS scores

8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
6.5NIST NVDAV:N/AC:L/Au:S/C:P/I:P/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-377Insecure Temporary File
CWE-668Exposure of Resource to Wrong Sphere
T1005Data from Local System

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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