Junglewise Threat Intelligence

CVE-1999-0193: Ascend and 3Com Routers denial of service via zero length TCP option

CVE-1999-0193 · Severity: medium · CVSS 5 · Published 1997-12-01

Executive brief

A vulnerability in Ascend and 3Com routers allows an attacker to remotely restart the device. These routers are critical networking components used to direct internet and corporate traffic. By triggering a reboot, an attacker can cause a temporary loss of connectivity, disrupting business operations and network availability.

Technical details

A denial of service vulnerability exists in the TCP/IP stack implementation of various Ascend and 3Com routers. The flaw is triggered when the device processes a TCP packet containing a zero-length TCP option. An unauthenticated remote attacker can exploit this by sending a specially crafted packet to the device, causing the router to crash and reboot. This results in a temporary denial of service for all network traffic passing through the affected hardware.

Affected products

  • Ascend Routers
  • 3Com Routers

Timeline

  • 1997-12-01: disclosed: Initial publication date

References