CVE-2018-0369

Severity: high (CVSS 8.6 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 2.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2018-07-16 · updated 2026-06-17
Weakness: CWE-20

Description

A vulnerability in the reassembly logic for fragmented IPv4 packets of Cisco StarOS running on virtual platforms could allow an unauthenticated, remote attacker to trigger a reload of the npusim process, resulting in a denial of service (DoS) condition. There are four instances of the npusim process running per Service Function (SF) instance, each handling a subset of all traffic flowing across the device. It is possible to trigger a reload of all four instances of the npusim process around the same time. The vulnerability is due to improper handling of fragmented IPv4 packets containing options. An attacker could exploit this vulnerability by sending a malicious IPv4 packet across an affected device. An exploit could allow the attacker to trigger a restart of the npusim process, which will result in all traffic queued toward this instance of the npusim process to be dropped while the process is restarting. The npusim process typically restarts within less than a second. This vulnerability affects: Cisco Virtualized Packet Core-Single Instance (VPC-SI), Cisco Virtualized Packet Core-Distributed Instance (VPC-DI), Cisco Ultra Packet Core (UPC). Cisco Bug IDs: CSCvh29613.

Affected products

Cisco StarOS: from 21.3 before 21.3.15; from 21.4 before 21.5.7; from 21.6 before 21.6.4 — fixed in 21.3.15, 21.5.7, 21.6.4

How to fix

Upgrade to a fixed version: Cisco StarOS 21.3.15, 21.5.7, 21.6.4. Check the vendor advisory for mitigations.

References

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