CVE-2025-61944: TP-Link Archer AX53 Buffer Overflow Flaw

CVE-2025-61944 Overview

CVE-2025-61944 is a heap-based buffer overflow vulnerability affecting TP-Link Archer AX53 v1.0 routers. The vulnerability exists in the tmpserver modules and allows authenticated adjacent attackers to cause a segmentation fault or potentially execute arbitrary code via a specially crafted network packet containing an excessive number of fields with zero-length values.

Critical Impact

Authenticated attackers on the same network segment can exploit this vulnerability to crash the router or potentially achieve arbitrary code execution, compromising the entire network infrastructure.

Affected Products

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

Discovery Timeline

• 2026-02-03 - CVE-2025-61944 published to NVD
• 2026-02-04 - Last updated in NVD database

Technical Details for CVE-2025-61944

Vulnerability Analysis

This vulnerability is classified as CWE-122 (Heap-based Buffer Overflow). The flaw resides in the tmpserver modules of the TP-Link Archer AX53 v1.0 router firmware. When processing network packets, the affected code fails to properly validate the number and size of input fields, particularly when handling packets containing numerous fields with zero-length values.

The adjacent network attack vector means an attacker must be on the same network segment as the vulnerable device. Authentication is required to exploit this vulnerability, which provides some mitigation against opportunistic attacks but still presents significant risk in environments where authenticated users may be malicious or compromised.

Root Cause

The root cause of this vulnerability lies in improper bounds checking within the tmpserver modules when parsing network packet fields. When a specially crafted packet arrives containing an excessive number of fields with zero-length values, the code allocates heap memory without adequate size validation. This leads to heap corruption when the malformed data is processed, resulting in either a segmentation fault (denial of service) or potentially allowing an attacker to manipulate heap memory in a way that enables arbitrary code execution.

Attack Vector

The attack requires adjacent network access, meaning the attacker must be positioned on the same local network segment as the target router. The attack is executed by:

1. Authenticating to the router (valid credentials required)
2. Sending a maliciously crafted network packet to the tmpserver module
3. The packet contains an excessive number of fields with zero-length values
4. This triggers the heap-based buffer overflow condition

The vulnerability is exploited by crafting a network packet with an unusually large number of fields, each containing zero-length values. This packet structure bypasses normal input validation and triggers heap memory corruption in the tmpserver module. Successful exploitation can result in either a denial of service condition (router crash) or arbitrary code execution with the privileges of the affected service. For detailed technical analysis, refer to the Talos Intelligence Vulnerability Reports.

Detection Methods for CVE-2025-61944

Indicators of Compromise

• Unexpected router crashes or reboots without administrator action
• Unusual network traffic patterns targeting the router's internal services
• Authentication logs showing repeated access attempts followed by service failures
• Memory corruption indicators in router system logs if available

Detection Strategies

• Monitor for abnormal packet structures targeting the router's management interfaces
• Implement network intrusion detection rules to identify packets with excessive zero-length fields
• Review authentication logs for suspicious patterns of authenticated access followed by service disruption
• Deploy network monitoring to detect anomalous traffic from authenticated devices toward the router

Monitoring Recommendations

• Enable comprehensive logging on the TP-Link Archer AX53 router to capture service crashes
• Implement network segmentation to limit adjacent network exposure
• Use network monitoring tools to baseline normal traffic patterns and alert on deviations
• Consider implementing a network-based intrusion detection system (IDS) on the local network segment

How to Mitigate CVE-2025-61944

Immediate Actions Required

• Check the current firmware version of all TP-Link Archer AX53 v1.0 devices in your environment
• Visit the TP-Link Archer AX53 Firmware Download page to obtain the latest patched firmware
• Restrict network access to trusted devices only until firmware updates can be applied
• Review the TP-Link FAQ on Security Issue for additional vendor guidance

Patch Information

TP-Link has acknowledged this vulnerability. Administrators should download the latest firmware from the official TP-Link support page for the Archer AX53 v1.0. The vulnerable firmware versions are those through 1.3.1 Build 20241120. Visit TP-Link Archer AX53 Firmware Download to obtain updated firmware.

Workarounds

• Restrict physical and wireless network access to trusted users and devices only
• Implement strong authentication credentials and regularly rotate passwords
• Consider network segmentation to isolate the router from untrusted devices
• Monitor for unusual router behavior and enable logging where available
• Disable unnecessary services on the router until the patch is applied

# Configuration example
# Verify current firmware version via router web interface
# Navigate to: Advanced > System Tools > Firmware Upgrade
# Compare against vulnerable version 1.3.1 Build 20241120
# Download and apply latest firmware from TP-Link support portal