VulnerabilityPublished 15 Jul 2024Updated 2 Aug 2024

CVE-2024-40416: Stack-based Buffer Overflow

Source CVE Database V5

Not known to be exploited · CVSS 6.5 Medium.

Data as of 26 Oct 2026, 09:15 UTC

CVSS 3.1 base score

6.5Medium

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

EPSS: 0.5% chance of exploitation in 30 days – higher than 47% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Adjacent
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

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

Attack Vector: Adjacent: The vulnerable component is bound to the network stack, but the attack is limited at the protocol level to a logically adjacent topology. This can mean an attack must be launched from the same shared physical (e.g., Bluetooth or IEEE 802.11) or logical (e.g., local IP subnet) network, or from within a secure or otherwise limited administrative domain (e.g., MPLS, secure VPN to an administrative network zone).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 15 Jul 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC 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

AI-suggested

1. Restrict network access to the router’s management interface by implementing firewall rules or network segmentation to limit exposure to trusted devices only. 2. Disable remote management features if not required, especially WAN-side access to the /goform/SetVirtualServerCfg endpoint. 3. Monitor router logs and network traffic for unusual requests targeting the /goform/SetVirtualServerCfg endpoint or signs of device instability such as unexpected reboots or crashes. 4. Regularly check for firmware updates from Tenda and apply patches promptly once available. 5. Consider replacing affected devices with models from vendors with a stronger security track record if timely patches are not forthcoming. 6. Employ network intrusion detection systems (NIDS) with signatures for buffer overflow attempts targeting Tenda routers to detect exploitation attempts. 7. Educate users about the risks of exposing router management interfaces to untrusted networks and enforce strong network access controls. 8. If possible, implement network-level anomaly detection to identify and block malformed packets that could trigger the buffer overflow.

Description

A vulnerability in /goform/SetVirtualServerCfg in the sub_6320C function in Tenda AX1806 1.0.0.1 firmware leads to stack-based buffer overflow.

Impact

The primary impact of CVE-2024-40416 is on the availability of affected Tenda AX1806 routers. Successful exploitation can cause the device to crash or reboot, resulting in denial of service for users relying on the router for internet connectivity. This can disrupt business operations, remote work, and critical communications, especially in small offices or home environments where this router is deployed. Although confidentiality and integrity are not directly impacted according to the CVSS vector, repeated or targeted attacks could degrade network reliability and trust in the device. The lack of authentication requirement and user interaction lowers the barrier for attackers with network access to exploit this vulnerability. Since no known exploits are currently in the wild, the immediate risk is moderate, but the potential for future exploitation remains. Organizations using these routers in sensitive or critical environments could face operational disruptions and should prioritize mitigation. Additionally, the vulnerability could be leveraged as part of a larger attack chain to facilitate lateral movement or network reconnaissance if combined with other vulnerabilities.

CWE-121Stack-based Buffer Overflow (opens in a new tab)
Variant weaknessLikelihood of exploit: HighCWE Top 25 (2025): #14
A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).
Operation · Build and Compilation · Environment Hardening
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…
Architecture and Design
Use an abstraction library to abstract away risky APIs. Not a complete solution.
Implementation
Implement and perform bounds checking on input.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

github.com/Feng-ZZ-pwn/IOT/blob/main/Tenda%20AX_1806/3/SetVirtualServerCfg.md (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 28 Feb 2026, 05:18 UTC

WeaknessesCWE-121

Technical details

References

Community reviews

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