VulnerabilityPublished 18 Mar 2026

CVE-2025-31703: dahua NVR2-4KS3 · Authentication Bypass by Primary Weakness

Affects dahua NVR2-4KS3Source CVE Database V5

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Not known to be exploited · CVSS 2.4 Low.

Data as of 31 Oct 2026, 08:20 UTC

CVSS 4.0 base score

2.4Low

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 21% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N

Attack Vector: Physical
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: Low
Vulnerable system integrity: Low
Vulnerable system availability: None
Subsequent system confidentiality: Low
Subsequent system integrity: Low
Subsequent system availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Physical: The attack requires the attacker to physically touch or manipulate the vulnerable system. Physical interaction may be brief (e.g., evil maid attack) or persistent.
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the Vulnerable System.
Vulnerable system integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact to the Vulnerable System.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
Subsequent system confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the Subsequent System.
Subsequent system integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact to the Subsequent System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 18 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
dahuaNVR2-4KS3	Affected =Versions which Build time prior to 3rd March 2026	Fixed in–
dahuaXVR4232AN-I/T	Affected =Versions which Build time prior to 3rd March 2026	Fixed in–
dahuaXVR1B16H-I/T	Affected =Versions which Build time prior to 3rd March 2026	Fixed in–

AI-suggested

To mitigate this vulnerability, organizations should implement strict physical security controls to prevent unauthorized access to Dahua NVR2-4KS3 devices, including securing device locations and restricting access to trusted personnel only. Monitoring and logging physical access attempts can help detect suspicious activity. Organizations should regularly check for firmware updates from Dahua addressing this vulnerability and apply patches promptly once available. If firmware updates are not yet released, consider disabling or physically blocking access to the serial port where feasible. Network segmentation should be employed to isolate surveillance devices from critical network segments to limit potential lateral movement. Additionally, conduct regular security audits of physical and network controls around surveillance infrastructure. Employing tamper-evident seals or enclosures can also deter or reveal unauthorized physical access attempts. Finally, maintain an inventory of affected devices to prioritize remediation efforts.

Description

A vulnerability found in Dahua NVR/XVR device. A third-party malicious attacker with physical access to the device may gain access to a restricted shell via the serial port, and bypasses the shell's authentication mechanism to escalate privileges.

Impact

The primary impact of this vulnerability is unauthorized access and privilege escalation on Dahua NVR2-4KS3 devices, which are commonly used for video surveillance in enterprise, government, and critical infrastructure environments. An attacker with physical access could bypass authentication and gain control over the device's shell, potentially allowing them to alter device configurations, disable security features, or extract sensitive video data. This could compromise the confidentiality and integrity of surveillance footage and disrupt monitoring capabilities, impacting physical security operations. While the requirement for physical access limits the scope, environments with less stringent physical controls or exposed devices (e.g., remote or outdoor installations) are at higher risk. The vulnerability could also be leveraged as a foothold for lateral movement within a network, increasing overall organizational risk. Given the widespread use of Dahua devices globally, the impact could be significant in sectors relying heavily on video surveillance for security and operational monitoring.

CWE-305Authentication Bypass by Primary Weakness (opens in a new tab)
Base weaknessOWASP Top 10 A07:2025: Authentication Failures (opens in a new tab)
The authentication algorithm is sound, but the implemented mechanism can be bypassed as the result of a separate weakness that is primary to the authentication error.
OWASP Cheat Sheets
OWASP Authentication (opens in a new tab)
OWASP ASVS 4.0.3
V2.8.5 (opens in a new tab)
V2.8.4 (opens in a new tab)
V9.2.3 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

dahuasecurity.com/about-dahua/trust-center/dahua-psirt/security-advisory-%E2%80%93-vulnerability-found-in-dahua-nvr-xvr-device (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 18 Mar 2026, 07:59 UTC

WeaknessesCWE-305

Technical details

References

Community reviews

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