Vulnerability report

Active exploitation observed Confirmed confidence Not in CISA KEV

CVE-2024-3721

DVR-4104 Command Injection

TBK / DVR-4104 · 0

Watch CVE-2024-3721 Browse KEV feed
Severity
CVSS 6.3 · Medium
Confidence
Confirmed
Exploit status
Observed in sensors
EPSS
86.5%
First observed
09 Jul 2026
Last observed
14 Oct 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. Previdian sensors observed exploitation attempts with confirmed confidence. Also confirmed by third-party sources.

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.

tbkvision Affected
tbk-dvr4104
0
tbkvision Affected
tbk-dvr4216
0
TBK Affected
DVR-4104
20240412
TBK Affected
DVR-4216
20240412
View vendor advisory (opens in new tab)
Published
13 Apr 2024
Exploitation Reported
22 Apr 2025
Attack vector
Remote
Complexity
Low
Privileges
Low
User interaction
None

CVE References

Exploitation evidence

Why Previdian 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

A trusted third party reported exploitation.

Active exploitation observed

Previdian sensor

First observed 09 Jul 2026

Previdian first observed exploitation attempts targeting this vulnerability in our honeypot sensors.

Known exploited vulnerability sources

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

Learn about Pro API access
Source Added
The Shadowserver First 2025-04-28 00:00 UTC
Previdian Sensors 2026-07-14 15:58 UTC
The Hacker News 2026-10-05 15:33 UTC

Operational indicators for this CVE are listed under Detection.

Sensor telemetry

First-party evidence of exploitation activity

Previdian sensors recorded exploitation attempts targeting this vulnerability. The cards and chart show volume, unique attackers, and daily activity.

114

Attempts observed

30

Unique attacker IPs

10

Attacker countries

BR · CO · DE · ER · FR · IT · NL · SC · SG · US

44

Sensors observed

CVE-2024-3721 exploitation attempts over the last 82 days

Daily events observed by Previdian sensors

Updated 18 Oct 2026

0
1
0
9
9
10
1
0
0
0
1
1
0
0
0
0
0
0
0
0
0
0
0
3
3
3
1
0
0
0
0
0
0
0
0
0
3
0
1
0
1
0
3
3
0
0
0
0
2
5
3
1
1
2
6
5
2
2
0
0
0
0
0
0
1
6
1
0
0
0
0
0
0
0
3
1
0
20
0
0
0
0
29 Jul 15 Aug 1 Sep 18 Sep 18 Oct

First observed 09 Jul 2026 · Last observed 14 Oct 2026

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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
User-Agents
Callback hosts
20
3
19

Request targets and User-Agents available in Pro. Callback host details available in Enterprise.

Scanner coverage

No scanner integrations recorded yet.

Virtual patch status

Previdian virtual patch guidance is available for this CVE.

AWS WAF Cloudflare ModSecurity

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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Virtual Patch Detail

Compensating WAF rules for this CVE.

Available

Enterprise feature. Virtual patch rule content and deployable vendor exports (ModSecurity, Cloudflare, AWS WAF) are available to Previdian Enterprise users.

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Risk and context

Severity, weaknesses, and research context

CVSS v3.1

6.3 Medium

Potential damage if exploited. Separate from whether attackers are using it.

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

EPSS

86.5%

Estimated chance of exploitation in the next 30 days. Previdian's warning comes from evidence, not this score.

Weaknesses

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

Recent mention · The Hacker News

Realtek Jungle SDK Exploit Attempts Deliver Cling Botnet With STUN-Based C2

Ravie LakshmananOct 05, 2026Vulnerability / Malware Threat actors have been observed attempting to exploit a now-patched critical security flaw impacting the Realtek Jungle software development kit (SDK) to deploy a botnet malware called Cling. "Cling is notable not because...

Read full advisory

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

  1. 15:33 UTC

    KEV confirmed by The Hacker News

    Exploitation attested by an external source

  2. 12:35 UTC

    Virtual patch available

    Compensating WAF rule available to block exploitation

  3. 15:12 UTC

    Indicators of compromise added (34)

    Indicators of compromise recorded

  4. 15:12 UTC

    Observed by Previdian sensors

    Evidence-backed exploitation signal

  5. 00:00 UTC

    Added to Previdian KEV Feed

    High-confidence, third-party attested exploitation

  6. 12:00 UTC

    CVE published

    Vulnerability disclosed publicly

  7. 17:19 UTC

    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

Sample API response 
{
  "cve_id": "CVE-2024-3721",
  "confidence": "Confirmed",
  "cvss_score": 6.3,
  "cvss_estimated": false,
  "epss_score": 0.86489,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": true
  },
  "sensor_telemetry": { "attempts": 114, "sensors": 44 }
}