CyberSecBulletin
CVE-2024-39949NVD status: Modified

NVR4XXX: Reachable Assertion

Published Updated By the CyberSecBulletin desk

CVE-2024-39949 is a high-severity reachable assertion vulnerability in NVR4XXX from Dahua, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected NVR4XXX versions: NVR4XXX Versions which Build time before 2023/12/13. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.56% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update nvr4xxx_firmware to 2023.12.13 or a later version.
  2. Update Nvr4104-4ks2/l Firmware to 4.003.0000000.1.r.240515 or a later version.
  3. Update Nvr4116-4ks2/l Firmware to 4.003.0000000.1.r.240515 or a later version.
  4. Read the advisory on dahuasecurity.com for workarounds and exact fixed builds.
  5. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
DahuaNVR4XXXNVR4XXX Versions which Build time before 2023/12/13Not stated
Dahuasecuritynvr4xxx_firmwarebefore 2023.12.132023.12.13
DahuasecurityNvr4104-4ks2/l Firmwarebefore 4.003.0000000.1.r.2405154.003.0000000.1.r.240515
DahuasecurityNvr4108-4ks2/l Firmware4.003.0000000.1.r.240515Not stated
DahuasecurityNvr4116-4ks2/l Firmwarebefore 4.003.0000000.1.r.2405154.003.0000000.1.r.240515
DahuasecurityNvr4104-p-4ks2/l Firmwarebefore 4.003.0000000.1.r.2405154.003.0000000.1.r.240515
DahuasecurityNvr4108-p-4ks2/l Firmwarebefore 4.003.0000000.1.r.2405154.003.0000000.1.r.240515
DahuasecurityNvr4108-8p-4ks2/l Firmwarebefore 4.003.0000000.1.r.2405154.003.0000000.1.r.240515
DahuasecurityNvr4116-8p-4ks2/l Firmwarebefore 4.003.0000000.1.r.2405154.003.0000000.1.r.240515
DahuasecurityNvr4104hs-4ks2/l Firmwarebefore 4.003.0000000.1.r.2405154.003.0000000.1.r.240515
DahuasecurityNvr4108hs-4ks2/l Firmwarebefore 4.003.0000000.1.r.2405154.003.0000000.1.r.240515
DahuasecurityNvr4104hs-p-4ks2/l Firmwarebefore 4.003.0000000.1.r.2405154.003.0000000.1.r.240515
DahuasecurityNvr4108hs-p-4ks2/l Firmwarebefore 4.003.0000000.1.r.2405154.003.0000000.1.r.240515
DahuasecurityNvr4108hs-8p-4ks2/l Firmwarebefore 4.003.0000000.1.r.2405154.003.0000000.1.r.240515
DahuasecurityNvr4116hs-8p-4ks2/l Firmwarebefore 4.003.0000000.1.r.2405154.003.0000000.1.r.240515
DahuasecurityNvr4204-4ks2/l Firmwarebefore 4.003.0000000.1.r.2405154.003.0000000.1.r.240515
DahuasecurityNvr4208-4ks2/l Firmwarebefore 4.003.0000000.1.r.2405154.003.0000000.1.r.240515
DahuasecurityNvr4216-4ks2/l Firmwarebefore 4.003.0000000.1.r.2405154.003.0000000.1.r.240515
DahuasecurityNvr4204-p-4ks2/l Firmwarebefore 4.003.0000000.1.r.2405154.003.0000000.1.r.240515
DahuasecurityNvr4208-8p-4ks2/l Firmwarebefore 4.003.0000000.1.r.2405154.003.0000000.1.r.240515
DahuasecurityNvr4216-16p-4ks2/l Firmwarebefore 4.003.0000000.1.r.2405154.003.0000000.1.r.240515
DahuasecurityNvr4232-4ks2/l Firmwarebefore 4.003.0000000.1.r.2405154.003.0000000.1.r.240515
DahuasecurityNvr4232-16p-4ks2/l Firmwarebefore 4.003.0000000.1.r.2405154.003.0000000.1.r.240515
DahuasecurityNvr4116hs-4ks2/l Firmwarebefore 4.003.0000000.1.r.2405154.003.0000000.1.r.240515
DahuasecurityNvr4416-4ks2/i Firmwarebefore 4.001.0000001.6.r.2407254.001.0000001.6.r.240725

Version data comes from the organisation that assigned the CVE; 33 further products are omitted here. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
NoneNo data is disclosed.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.17.5HighCNA (dahuatech.com)
CVSS 3.17.5HighNVD

Official description

A vulnerability has been found in Dahua products. Attackers can send carefully crafted data packets to the interface with vulnerabilities, causing the device to crash.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Reachable Assertion

The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary.

How developers prevent this class of flaw

  • If the assertion statement is required (e.g., for security or reliability), change the invoking code to avoid the conditions that trigger the assertion.
  • Consider changing the assertion to some other less fatal error. This might not be easy to implement, since other code may be needed to handle the error.
  • Make sensitive open/close operations non-reachable from directly user-controlled data (e.g. open/close resources)

More Reachable Assertion vulnerabilities (CWE-617)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in NVR4XXX

All NVR4XXX vulnerabilities

Recent Reachable Assertion vulnerabilities

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