CVE-2025-4354 Overview
CVE-2025-4354 is a stack-based buffer overflow in the D-Link DAP-1520 wireless range extender running firmware version 1.10B04_BETA02. The flaw resides in the check_dws_cookie function within the /storage component. An attacker can manipulate input to overflow the stack buffer and corrupt adjacent memory on the device. The vulnerability is exploitable over the network, and a public disclosure has been released describing the issue. The weakness is tracked under [CWE-119] (Improper Restriction of Operations within the Bounds of a Memory Buffer) and [CWE-787] (Out-of-Bounds Write).
Critical Impact
Remote attackers with low-level privileges can corrupt memory in check_dws_cookie, potentially leading to arbitrary code execution or full device compromise on affected DAP-1520 range extenders.
Affected Products
- D-Link DAP-1520 wireless range extender (hardware)
- D-Link DAP-1520 firmware version 1.10B04_BETA02
- Deployments exposing the device web management interface to untrusted networks
Discovery Timeline
- 2025-05-06 - CVE-2025-4354 published to NVD
- 2025-05-13 - Last updated in NVD database
Technical Details for CVE-2025-4354
Vulnerability Analysis
The vulnerability exists in the check_dws_cookie function handling requests against the /storage path on the DAP-1520. The function copies attacker-controlled cookie data into a fixed-size stack buffer without enforcing length validation. When the input exceeds the buffer boundary, adjacent stack memory including the saved return address can be overwritten. Successful exploitation yields control over program flow on a MIPS-based embedded device with limited memory protections. The DAP-1520 lacks modern mitigations such as stack canaries and full address space layout randomization, which increases the reliability of memory corruption exploitation.
Root Cause
The root cause is missing bounds checking on cookie data parsed by check_dws_cookie. The function trusts the length of attacker-supplied input when populating a local stack buffer. This pattern aligns with both [CWE-119] and [CWE-787], reflecting an unchecked memory copy that writes past the allocated buffer. Embedded firmware compiled without stack protection compounds the impact.
Attack Vector
An attacker on the same network as the DAP-1520, or on any network where the management interface is reachable, can send a crafted HTTP request targeting the /storage endpoint with an oversized or malformed cookie value. The request requires low privileges to trigger the vulnerable code path. No user interaction is required, and the attack can be scripted against any reachable device. Technical write-up details are documented in the GitHub Documentation for DAP-1520 and VulDB #307472.
No verified exploit code is published. The public disclosure describes the vulnerable function and request structure but does not include a weaponized payload.
Detection Methods for CVE-2025-4354
Indicators of Compromise
- HTTP requests to /storage endpoints on DAP-1520 devices containing abnormally long or malformed Cookie header values
- DAP-1520 management interface crashes, reboots, or service restarts coinciding with inbound HTTP traffic
- Unexpected outbound connections originating from the DAP-1520 toward unknown hosts following inbound web requests
Detection Strategies
- Inspect web access logs and network captures for Cookie header values exceeding typical session token length on requests to the /storage URI
- Monitor for repeated HTTP requests to the DAP-1520 management interface from a single source within short time windows
- Alert on firmware version 1.10B04_BETA02 instances exposed beyond trusted management segments
Monitoring Recommendations
- Capture and retain HTTP traffic to and from DAP-1520 devices for retrospective analysis
- Track device availability and reboot frequency as an early signal of exploitation attempts
- Enumerate all DAP-1520 units across the environment and confirm their firmware revisions on a recurring schedule
How to Mitigate CVE-2025-4354
Immediate Actions Required
- Remove DAP-1520 management interfaces from internet exposure and restrict access to dedicated management VLANs
- Block untrusted source addresses from reaching the device web interface using upstream firewall rules
- Disable remote management features on the DAP-1520 until a vendor patch is available
- Inventory all DAP-1520 deployments and prioritize replacement of units running firmware 1.10B04_BETA02
Patch Information
No vendor patch is referenced in the published advisory at the time of NVD publication. Administrators should monitor the D-Link security bulletin channels for firmware updates addressing check_dws_cookie. Consult the VulDB CTI ID #307472 entry for tracking updates. Until a fixed firmware image is released, compensating controls remain the primary mitigation.
Workarounds
- Place the DAP-1520 behind a network firewall that denies all inbound HTTP traffic from non-administrative hosts
- Apply ACLs on the upstream switch or router to permit management traffic only from designated administrator workstations
- Replace end-of-support DAP-1520 units with a currently supported wireless extender that receives security updates
# Example: restrict access to DAP-1520 management interface using iptables on an upstream gateway
iptables -A FORWARD -p tcp -d <DAP-1520-IP> --dport 80 -s <ADMIN-SUBNET> -j ACCEPT
iptables -A FORWARD -p tcp -d <DAP-1520-IP> --dport 80 -j DROP
iptables -A FORWARD -p tcp -d <DAP-1520-IP> --dport 443 -s <ADMIN-SUBNET> -j ACCEPT
iptables -A FORWARD -p tcp -d <DAP-1520-IP> --dport 443 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
