CyberSecBulletin
CVE-2024-39950NVD status: Modified

NVR4XXX and IPC-HX8XXX: Stack-based Buffer Overflow

Published Updated By the CyberSecBulletin desk

CVE-2024-39950 is a critical-severity stack-based buffer overflow vulnerability in NVR4XXX and IPC-HX8XXX from Dahua, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. There is no confirmed exploitation so far. EPSS estimates a 0.49% chance of exploitation within 30 days, which is low compared with other CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update nvr4832-i to 2024.2.2 or a later version.
  2. Update ipc-hf8xxx_firmware to 2024.2.2 or a later version.
  3. Update ipc-hfw8xxx to 2024.2.2 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
DahuaNVR4XXX and IPC-HX8XXXNot specified in the recordNot stated
Dahuasecuritynvr4832-ibefore 2024.2.22024.2.2
Dahuasecurityipc-hf8xxx_firmwarebefore 2024.2.22024.2.2
Dahuasecurityipc-hfw8xxxbefore 2024.2.22024.2.2
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

Version data comes from the organisation that assigned the CVE; 35 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
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

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

Scoring systemScoreSeverityScored by
CVSS 3.18.6HighCNA (dahuatech.com)
CVSS 3.19.8CriticalNVD

Official description

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

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

The underlying weakness: Stack-based Buffer Overflow

The product writes past the end of a buffer that was allocated on the stack.

How developers prevent this class of flaw

  • Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.
  • Use an abstraction library to abstract away risky APIs. Not a complete solution.
  • Implement and perform bounds checking on input.

More Stack-based Buffer Overflow vulnerabilities (CWE-121)

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

Recent Stack-based Buffer Overflow vulnerabilities

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