CVE-2025-62405: TP-Link Archer AX53 Buffer Overflow Flaw

CVE-2025-62405 Overview

A heap-based buffer overflow vulnerability has been identified in the TP-Link Archer AX53 v1.0 router, specifically within the tmpserver modules. This vulnerability allows authenticated adjacent attackers to cause a segmentation fault or potentially execute arbitrary code via a specially crafted network packet containing a field whose length exceeds the maximum expected value.

Critical Impact

Authenticated attackers on the adjacent network can potentially achieve arbitrary code execution on the affected TP-Link router, compromising network security and potentially enabling further attacks on connected devices.

Affected Products

• TP-Link Archer AX53 v1.0 through firmware version 1.3.1 Build 20241120

Discovery Timeline

• 2026-02-03 - CVE CVE-2025-62405 published to NVD
• 2026-02-04 - Last updated in NVD database

Technical Details for CVE-2025-62405

Vulnerability Analysis

This heap-based buffer overflow (CWE-122) resides in the tmpserver modules of the TP-Link Archer AX53 v1.0 firmware. The vulnerability occurs when the router processes network packets containing fields that exceed the expected maximum length. The tmpserver component fails to properly validate input length boundaries before copying data to heap-allocated memory buffers, allowing an attacker to overflow the buffer and corrupt adjacent heap memory structures.

The exploitation requires the attacker to be authenticated and positioned on an adjacent network segment, limiting the attack surface to local network environments. However, once these conditions are met, successful exploitation can lead to denial of service through segmentation faults or potentially full arbitrary code execution on the router's embedded operating system.

Root Cause

The root cause of this vulnerability stems from insufficient input validation in the tmpserver modules. When processing incoming network packets, the firmware does not adequately verify that the length of certain fields falls within expected boundaries. This allows oversized data to be written to fixed-size heap buffers, resulting in a classic heap-based buffer overflow condition.

The lack of proper bounds checking before memory copy operations enables attackers to write beyond the allocated buffer boundaries, potentially overwriting critical heap metadata or adjacent data structures used by the router's firmware.

Attack Vector

The attack vector requires adjacent network access, meaning the attacker must be on the same local network segment as the target router. Additionally, authentication is required, indicating the attacker must have valid credentials or access to an authenticated session.

The attack is executed by sending specially crafted network packets to the vulnerable tmpserver module. These malicious packets contain fields with lengths exceeding the maximum expected values, triggering the buffer overflow condition when the router attempts to process the oversized data.

Due to the nature of heap-based overflows, sophisticated attackers may be able to manipulate heap layout and metadata to achieve arbitrary code execution, potentially gaining full control over the router. This could enable attackers to intercept network traffic, modify DNS settings, or pivot to attack other devices on the network.

Detection Methods for CVE-2025-62405

Indicators of Compromise

• Unexpected router crashes, reboots, or service interruptions affecting the tmpserver process
• Unusual network traffic patterns originating from or directed at the router's management interfaces
• Evidence of segmentation faults in router system logs related to tmpserver modules
• Unauthorized configuration changes on the router or suspicious authenticated sessions

Detection Strategies

• Monitor router system logs for segmentation fault errors or abnormal process terminations in tmpserver modules
• Implement network intrusion detection rules to identify malformed or oversized packets targeting router management services
• Deploy network monitoring to detect unusual traffic patterns from authenticated sessions on the local network segment
• Regularly audit router configurations for unauthorized changes that may indicate compromise

Monitoring Recommendations

• Enable comprehensive logging on the TP-Link Archer AX53 router and forward logs to a centralized SIEM solution
• Implement network segmentation to limit adjacent network access and reduce the attack surface
• Monitor for firmware version changes and ensure only authorized updates are applied
• Conduct periodic security assessments of network infrastructure including router firmware versions

How to Mitigate CVE-2025-62405

Immediate Actions Required

• Update the TP-Link Archer AX53 v1.0 firmware to the latest available version that addresses this vulnerability
• Restrict administrative access to the router to trusted devices and users only
• Review and audit all authenticated user accounts on the router, removing any unnecessary or suspicious accounts
• Implement network segmentation to limit the potential impact of adjacent network attacks

Patch Information

TP-Link has released firmware updates to address this vulnerability. Affected users should download and install the latest firmware version from the official TP-Link Archer AX53 Firmware Download page. Additional guidance is available in the TP-Link Support FAQ 4943.

For additional technical details regarding this vulnerability, refer to Talos Intelligence Vulnerability Reports.

Workarounds

• Limit authenticated access to the router to only essential administrative users until the patch can be applied
• Implement strict network access controls to prevent unauthorized devices from accessing the adjacent network segment
• Consider temporarily disabling non-essential services on the router to reduce attack surface
• Use a firewall or access control list to restrict which devices can communicate with the router's management interfaces