Is CVE-2024-3721 actively exploited?

Yes. KEV Intelligence has observed exploitation attempts targeting this CVE. Confidence is confirmed.

What exploitation activity has KEV Intelligence observed?

KEV Intelligence sensors have observed 32 exploitation attempts, 11 unique attacker IPs, and 4 countries targeting CVE-2024-3721. First observed Jul 09, 2026; last observed Aug 09, 2026.

Which versions are affected?

CVE-2024-3721 affects TBK DVR-4104, DVR-4216. KEV Intelligence lists 4 version rows; examples include 0 and 20240412.

How should organizations remediate it?

Prioritize immediate patching and validate internet-facing exposure. Monitor for matching exploitation attempts in your environment.

No. CVE-2024-3721 is not currently listed in CISA KEV.

Vulnerability report

Active exploitation observed Confirmed confidence Not in CISA KEV

CVE-2024-3721

DVR-4104 Command Injection

TBK / DVR-4104 · 0

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Severity: CVSS 6.3 · Medium
Confidence: Confirmed
Exploit status: Observed in sensors
EPSS: 86.0%
First observed: 09 Jul 2026
Last observed: 09 Aug 2026

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2024-3721 is a vulnerability affecting TBK DVR-4104, DVR-4216. A vulnerability was found in TBK DVR-4104 and DVR-4216 up to 20240412 and classified as critical. This issue affects some unknown processing of the...

Is it exploited?

Yes. KEV Intelligence sensors observed exploitation attempts with confirmed confidence.

Who is affected?

TBK / DVR-4104 0.

What should we do?

Patch immediately, validate internet-facing exposure, and monitor for matching requests.

Overview

A vulnerability was found in TBK DVR-4104 and DVR-4216 up to 20240412 and classified as critical

A vulnerability was found in TBK DVR-4104 and DVR-4216 up to 20240412 and classified as critical. This issue affects some unknown processing of the file /device.rsp?opt=sys&cmd=___S_O_S_T_R_E_A_MAX___. The manipulation of the argument mdb/mdc leads to os command injection. The attack may be initiated remotely. The exploit has been disclosed to the public and may be used. The identifier VDB-260573 was assigned to this vulnerability.

Eine kritische Schwachstelle wurde in TBK DVR-4104 and DVR-4216 bis 20240412 gefunden. Betroffen davon ist ein unbekannter Prozess der Datei /device.rsp?opt=sys&cmd=___S_O_S_T_R_E_A_MAX___. Mittels dem Manipulieren des Arguments mdb/mdc mit unbekannten Daten kann eine os command injection-Schwachstelle ausgenutzt werden. Die Umsetzung des Angriffs kann dabei über das Netzwerk erfolgen. Der Exploit steht zur öffentlichen Verfügung.

Vendor Product Affected Status

tbkvision tbk-dvr4104 0 Affected

tbkvision tbk-dvr4216 0 Affected

TBK DVR-4104 20240412 Affected

TBK DVR-4216 20240412 Affected

View vendor advisory

Published: 13 Apr 2024
Exploitation Reported: 22 Apr 2025
Attack vector: Remote
Complexity: Low
Privileges: Low
User interaction: None

CVE References

CVE Record CVE.org · CVE Record https://www.cve.org/CVERecord?id=CVE-2024-3721
Submit #314969 | TBK TBK DVR-4104, TBK DVR-4216 N/A Command Injection vuldb.com · Third-Party Advisory https://vuldb.com/?submit.314969
GitHub — netsecfish/tbk_dvr_command_injection github.com · Exploit https://github.com/netsecfish/tbk_dvr_command_injection
VDB-260573 | TBK DVR-4104/DVR-4216 os command injection vuldb.com · Technical Description https://vuldb.com/?id.260573
VDB-260573 | CTI Indicators (IOB, IOC, TTP, IOA) vuldb.com · Signature https://vuldb.com/?ctiid.260573

Exploitation evidence

Why KEV Intelligence marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

The Shadowserver

Recorded 22 Apr 2025

Independent exploitation attestation added to the KEV Intelligence record.

Active exploitation observed

KEV Intelligence sensor

First observed 09 Jul 2026

First-party sensor telemetry confirms matching exploitation attempts.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the KEV Intelligence Pro API.

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Source	Added
The Shadowserver First	2025-04-28 00:00 UTC
KEV Intelligence	2026-07-14 15:58 UTC

Operational indicators for this CVE are listed under Detection.

Sensor telemetry

First-party evidence of exploitation activity

Aggregate observations show the scale, recency, and distribution of activity without overstating sparse data.

Attempts observed

Unique attacker IPs

Attacker countries

DE · NL · SG · US

Sensors observed

Exploitation attempts over the last 43 days

Daily events observed by KEV Intelligence sensors

Updated 19 Aug 2026

8 Jul 17 Jul 26 Jul 4 Aug 19 Aug

First observed 09 Jul 2026 · Last observed 09 Aug 2026

Pro adds sensor region and window summaries. Enterprise adds raw IPs, paths, User-Agents, and payloads.

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Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets: 6
User-Agents: 2

Raw values available in Pro and Enterprise.

Scanner coverage

No scanner integrations recorded yet.

Virtual patch status

No KEV Intelligence virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

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Attacker IP Indicators

Attacker IP indicators observed · available in Pro and Enterprise.

Sensor-derived attacker IP indicators are available to Pro and Enterprise accounts under Detection and through the Pro API.

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Risk and context

Severity, weaknesses, and research context

CVSS v3.1

6.3 Medium

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L

EPSS

86.0%

Weaknesses

Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') CWE-78

All CVSS Scores

CVSS v3.1 6.3 Medium

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L

CVSS v3.0 6.3 Medium

CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L

CVSS v2.0 6.5 Medium

AV:N/AC:L/Au:S/C:P/I:P/A:P

Timeline

From disclosure to observed exploitation

09 Jul 2026
Observed by KEV Intelligence sensors

Evidence-backed exploitation signal
09 Jul 2026
Indicators of compromise added (16)

Indicators of compromise recorded
28 Apr 2025
Added to KEV Intelligence KEV Feed

High-confidence, third-party attested exploitation
13 Apr 2024
CVE published

Vulnerability disclosed publicly
12 Apr 2024
CVE ID reserved

Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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Evidence confidence and provenance
First-party sensor telemetry
PoC and scanner references
Affected versions and enrichment
Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2024-3721

Free JSON includes basic KEV fields

{
  "cve_id": "CVE-2024-3721",
  "confidence": "Confirmed",
  "cvss_score": 6.3,
  "cvss_estimated": false,
  "epss_score": 0.86008,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": true
  },
  "sensor_telemetry": { "attempts": 32, "sensors": 17 }
}

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