W20e Firmware
CVE-2026-24108
CRITICAL
Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
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AccessSend crafted HTTP request with oversized nptr parameter
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DeliveryParameter passed to getMibPrefix function
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Exploitsprintf concatenates without bounds checking
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ExecutionBuffer overflow overwrites memory
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ImpactExecute arbitrary code with device privileges
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A06:2021 - Vulnerable and Outdated Components
ASVS 5.0
V15 - Secure Coding and Architecture Buffer copy size validation
MITRE ATT&CK
1 technique across 1 tactic: Execution The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Exploitation Conditions | Tenda W20E running firmware V4.0br_V15.11.0.6 with default configuration exposing the vulnerable getMibPrefix function endpoint to unauthenticated network access. No authentication or special network setup required. |
| Impact | CVSS 9.8 with PoC. |
| Exploit ScenarioDerived | Buffer overflow via crafted HTTP request. |
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Alert meAnalysisAIv1 – Mar 12, 2026
Tenda W20E has a buffer overflow — second of eight critical vulnerabilities in this router firmware.
Earlier versions of this analysis (1)
Second Tenda W20E buffer overflow.
RemediationAI
Update firmware.
Affects your stack
Find out whether the stacks and servers you run are on an affected version.
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
CWE-120 in Tenda W20E.
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
Lifecycle Timeline
2DescriptionCVE.org
An issue was discovered in Tenda W20E V4.0br_V15.11.0.6. Attackers may exploit the vulnerability by controlling the value of nptr. When this value is passed into the getMibPrefix function and concatenated using sprintf without proper size validation, it could lead to a buffer overflow vulnerability.
Executive ViewAI
A critical vulnerability (CVE-2026-24108) affecting Tenda W20E routers allows remote attackers to gain unauthorized control with a CVSS score of 9.8. Organizations using this device model are at immediate risk of network compromise, data exfiltration, and potential lateral movement into corporate infrastructure, particularly if these devices serve as network entry points or manage critical connectivity.
Implement network segmentation isolating Tenda W20E devices from critical systems; disable remote administration and UPnP features; deploy WAF/IPS rules to detect exploitation attempts targeting the nptr parameter; restrict management access to whitelisted IP addresses only; increase logging and monitoring for these devices; consider temporary shutdown of non-essential W20E units until patching is available.
Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
A buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions.
Affected Products (CPE)CVE.org
Related Vulnerabilities in Tenda W20E Multiple Buffer Overflow Vulnerabilities
View all 7More in W20e Firmware
View allTenda W20E has a ninth buffer overflow in yet another CGI endpoint.
Tenda W20E has an eighth buffer overflow in addDhcpRules parameter.
Tenda W20E v15.11.0.6(US_W20EV4.0br_v15.11.0.6(1068_1546_841 is vulnerable to Buffer Overflow via function formSetSysTim
Tenda W20E v15.11.0.6 (US_W20EV4.0br_v15.11.0.6(1068_1546_841)_CN_TDC) is vulnerable to Buffer Overflow via function for
Tenda W20E router V15.11.0.6 (US_W20EV4.0br_V15.11.0.6(1068_1546_841)_CN_TDC) contains a stack overflow vulnerability in
Tenda W20E router V15.11.0.6 (US_W20EV4.0br_V15.11.0.6(1068_1546_841)_CN_TDC) contains a stack overflow vulnerability in
NVD
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EPSS
GitHub
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