External risk intelligence

Tenda i29 Buffer Overflow Vulnerability in sysScheduleRebootSet

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2023-50990

The affected product is a Tenda i29, which is a wireless access point. Such devices are network infrastructure components often managed via web-based administrative interfaces that are commonly exposed to the local network or, in some deployment scenarios, reachable via the internet-facing side of the management gateway.

Out-of-bounds Write

Tenda I29 Firmware

1.0.0.21.0.0.5

Halo Surface Signal: 4 out of 5 — likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

This advisory concerns a vulnerability identified in Tenda i29 wireless access points. The issue involves a buffer overflow that could allow unauthorized access and control over the device's functions. Given the critical nature of this vulnerability and the potential for remote exploitation, understanding its relevance to our deployed infrastructure is important.

A technical flaw exists in specific devices.
Critical vulnerability in network hardware could be exploited.
Confirm relevance and potential exposure in our environment.

Attack Path

How an attacker could exploit the issue

An attacker could exploit this vulnerability by sending specially crafted network requests to an exposed Tenda i29 device. This would target the `sysScheduleRebootSet` function, which handles reboot scheduling. If the attacker can provide an overly long input for the `rebootTime` parameter, it could overflow a buffer, potentially allowing for the execution of arbitrary code on the device.

Unauthenticated network access required.
Sending overly long `rebootTime` parameter.
Remote code execution on the device.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability in Tenda i29 devices could allow an unauthenticated attacker to cause a buffer overflow, potentially leading to the device being rendered inoperable. This could affect the device's ability to provide network services.

Device system integrity.
Remote unauthenticated network access.
Disruption of network services.

Operational Fix

Recommended remediation, mitigation, and detection steps

The Tenda i29 wireless access point is a network infrastructure component. Ownership typically resides with the team managing network hardware, which could be the infrastructure or network/security team. The first practical step is to identify all i29 devices, confirm their network exposure and business criticality, and then assign an owner for remediation planning.

Network/Infrastructure teams own the issue.
Verify device exposure and criticality.
Plan remediation based on risk.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

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Frequently asked questions

What is the Tenda i29?

The Tenda i29 is a wireless access point designed to provide network connectivity for users and devices. It functions as a piece of networking infrastructure, typically managed through a web-based interface that allows administrators to configure system settings like reboot schedules.

What does CVE-2023-50990 mean?

This CVE identifies a buffer overflow, which is a common memory safety issue categorized as CWE-787. In this instance, the device fails to properly check the length of data provided to the 'rebootTime' parameter. When this data exceeds the allocated memory space, it can overwrite adjacent memory, potentially allowing an attacker to hijack the device's operations.

How is this vulnerability triggered?

An attacker triggers this flaw by sending a specifically crafted network request to the device's scheduling function. The vulnerability is not triggered by standard usage or legitimate administrative commands; it requires the submission of an intentionally oversized input string designed to disrupt the device's memory management.

Why should I care about this Tenda i29 flaw?

According to Halo Surface Signal, the Tenda i29 is often managed via web interfaces that may be accessible from the local network. If these management interfaces are inadvertently exposed to the internet, the device becomes reachable by remote actors, significantly increasing the risk of unauthorized control or service disruption.

What are my first steps to address this?

Begin by conducting an inventory to locate all Tenda i29 devices within your network. Once identified, evaluate whether their management interfaces are accessible beyond strictly controlled internal segments. Coordinate with your network infrastructure team to prioritize these assets for remediation planning.

References

tenda.com/

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.