# CVE-2017-5632: ASUS RT-N56U denial of service in WAN connection

Source: https://junglewise.ai/threats/cve-2017-5632-asus-rt-n56u-denial-of-service-in-wan-connection  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2017-01-30. Updated: 2026-05-13  
License: CC BY 4.0 with a link back

CVE-2017-5632 · Severity: medium · CVSS 6.5 · Published 2017-01-30

The ASUS RT-N56U wireless router is susceptible to a flaw that allows a person on the same local network to crash the device's internet connection. By sending specific network probes, an attacker can cause a denial-of-service, effectively disconnecting the entire household or office from the internet. This requires the attacker to already have access to the local Wi-Fi or wired network.

Vendors: [ASUS](https://junglewise.ai/threats/vendors/asus).

## Quick answers

**Is CVE-2017-5632 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2017-5632 being exploited in the wild.

**How severe is CVE-2017-5632?** Medium severity, with a CVSS score of 6.5, published 30 January 2017.

**Which products and versions are affected?** ASUS RT-N56U Wireless Router 3.0.0.4.374_979.

**Is there a fix for CVE-2017-5632?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2017-5632 attacked?** It is attacked from the adjacent network, in a network appliance.

**Am I affected by CVE-2017-5632?** Check whether you run ASUS Rt-N56u or ASUS Rt-N56u Firmware. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A denial-of-service (DoS) vulnerability exists in the ASUS RT-N56U router running firmware version 3.0.0.4.374_979. The issue is triggered when the device processes specific network packets associated with OS fingerprinting, such as those generated by the 'nmap -O' command. An attacker located on the adjacent network (LAN) can exploit this to crash the Wide Area Network (WAN) interface, leading to a disconnection from the ISP. No authentication is required to trigger the crash. While the root cause is not explicitly detailed in the advisory, it likely involves an unhandled exception or resource exhaustion in the network stack when processing malformed or unexpected TCP/IP sequences used for OS detection.

## Affected products

- ASUS RT-N56U Wireless Router 3.0.0.4.374_979

## Timeline

- 2017-01-30: disclosed
- 2017-01-30: advisory

## References

- [http://www.securityfocus.com/bid/95857](http://www.securityfocus.com/bid/95857)
- [https://www.asus.com/Static_WebPage/ASUS-Product-Security-Advisory/](https://www.asus.com/Static_WebPage/ASUS-Product-Security-Advisory/)