CVE-2025-1538: D-Link DAP-1320 Buffer Overflow Flaw

CVE-2025-1538 Overview

CVE-2025-1538 is a heap-based buffer overflow vulnerability in the D-Link DAP-1320 wireless range extender running firmware version 1.00. The flaw resides in the set_ws_action function exposed through the /dws/api/ endpoint. Attackers can trigger the overflow remotely over the network, with the exploit publicly disclosed and available for use.

The vulnerability affects an end-of-life device that no longer receives security updates from D-Link. The weakness maps to [CWE-119] (improper restriction of operations within memory buffer bounds) and [CWE-787] (out-of-bounds write).

Critical Impact
Remote attackers can corrupt heap memory through the set_ws_action API endpoint, potentially leading to arbitrary code execution on an unsupported device with no vendor patch path.

Affected Products

D-Link DAP-1320 hardware revision (end-of-life)
D-Link DAP-1320 firmware version 1.00
All deployments exposing the /dws/api/ management interface

Discovery Timeline

2025-02-21 - CVE-2025-1538 published to NVD
2025-02-25 - Last updated in NVD database

Technical Details for CVE-2025-1538

Vulnerability Analysis

The defect lives in the set_ws_action handler reachable through the /dws/api/ HTTP interface on the DAP-1320 extender. The function processes attacker-supplied input without enforcing bounds on a heap-allocated buffer. Writing beyond the allocated region corrupts adjacent heap metadata and data structures.

The attack requires network access to the device and low-level privileges on the management interface, but no user interaction. Successful exploitation impacts confidentiality, integrity, and availability of the device. Because the DAP-1320 sits inline on the wireless path, compromise grants an attacker a foothold for traffic inspection, lateral movement, and persistence inside the network.

The D-Link DAP-1320 is no longer supported by the maintainer. No official patch will be issued for affected firmware.

Root Cause

The set_ws_action function fails to validate the length of attacker-controlled fields before copying them into a heap buffer. This produces a classic out-of-bounds write [CWE-787] and violates safe memory boundary handling [CWE-119]. Heap metadata corruption can be steered toward control-flow hijack on the embedded MIPS/ARM platform underpinning the device.

Attack Vector

An attacker reaches the vulnerable endpoint over HTTP by sending a crafted request to /dws/api/ invoking the set_ws_action operation. The request carries an oversized parameter that overflows the heap buffer during processing. The attack succeeds remotely without user interaction once the attacker can authenticate to the management interface with low privileges, which is trivial on devices using default or unchanged credentials.

No verified proof-of-concept code is published in the references provided. Technical details are documented in the Notion Vulnerability Report and tracked as VulDB #296479.

Detection Methods for CVE-2025-1538

Indicators of Compromise

HTTP POST requests to /dws/api/ containing the set_ws_action method with abnormally long parameter values
Unexpected reboots, watchdog resets, or httpd process crashes on DAP-1320 devices
Outbound connections from the extender to unfamiliar IP addresses, indicating possible post-exploitation activity
New or modified DNS, NTP, or firmware update settings on the device

Detection Strategies

Inspect HTTP traffic destined for DAP-1320 management interfaces and alert on set_ws_action requests exceeding expected field lengths
Profile baseline request sizes for /dws/api/ endpoints and flag statistical outliers
Correlate device administrative interface access with the source identities and times typical of legitimate operations

Monitoring Recommendations

Forward firewall and switch logs covering subnets that host D-Link extenders to a centralized analytics platform
Capture full packet metadata for management VLANs hosting end-of-life network gear
Track firmware version inventory to identify any remaining DAP-1320 v1.00 deployments

How to Mitigate CVE-2025-1538

Immediate Actions Required

Decommission and replace D-Link DAP-1320 devices, as the product is end-of-life with no vendor patch planned
If immediate replacement is not possible, isolate the device on a dedicated VLAN with no access to internal resources
Disable remote management and restrict the /dws/api/ interface to a trusted management host only
Rotate all administrative credentials on the device and any reused passwords elsewhere in the environment

Patch Information

No patch is available. D-Link confirms the DAP-1320 1.00 is outside the supported product lifecycle. Migration to a supported wireless extender from a vendor with an active security maintenance program is the only complete remediation. Vendor product information is published on the D-Link Official Website and the D-Link DAP-1320 Legacy Product Page.

Workarounds

Block inbound HTTP and HTTPS traffic to the DAP-1320 management interface at the upstream firewall
Place the device behind network segmentation that prevents untrusted clients from reaching /dws/api/
Monitor the device for crash, reboot, and configuration drift indicators until it can be retired

bash

# Example iptables rule restricting DAP-1320 management access to a single admin host
iptables -A FORWARD -p tcp -d <DAP1320_IP> --dport 80 -s <ADMIN_HOST_IP> -j ACCEPT
iptables -A FORWARD -p tcp -d <DAP1320_IP> --dport 80 -j DROP
iptables -A FORWARD -p tcp -d <DAP1320_IP> --dport 443 -s <ADMIN_HOST_IP> -j ACCEPT
iptables -A FORWARD -p tcp -d <DAP1320_IP> --dport 443 -j DROP