CVE-2021-47799Public exploit

Root shell via sudo-enabled mount bind

Published Jan 15, 2026 · Updated Jan 15, 2026

Local privilege escalation in Visual Tools DVR VX16 4.2.28.0 allows local users to gain root access through an unsafe sudo rule. The sudo configuration permits the mount utility to run as root, and mount can bind /bin/sh over /bin/mount before sudo executes it. A local shell under a low-privileged account is required; two mount invocations then start a root shell with full control of the recorder.

CVSS severity8.5
High
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Local privilege escalation in Visual Tools DVR VX16 4.2.28.0 allows local users to gain root access through an unsafe sudo rule. The sudo configuration permits the mount utility to run as root, and mount can bind /bin/sh over /bin/mount before sudo executes it. A local shell under a low-privileged account is required; two mount invocations then start a root shell with full control of the recorder.

The record

CVE
CVE-2021-47799
Published
Jan 15, 2026
Updated
Jan 15, 2026
Vendor
Visual Tools
Product
DVR VX16
Classifications
CWE-266, T1548.003
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 15, 2026Record 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=Visual Tools VX16 4.2.28.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Visual Tools · DVR VX16version=Visual Tools VX16 4.2.28.0

Published CVSS scores

6.2VulnCheckCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
8.5VulnCheckCVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-266Incorrect Privilege Assignment
T1548.003Sudo and Sudo Caching

Public exploit references

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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