Cisco StarOS npusim IPv4 Packet input validation

Summaryinfo

A vulnerability marked as problematic has been reported in Cisco StarOS. This affects an unknown function of the component npusim. Performing a manipulation as part of IPv4 Packet results in input validation. This vulnerability was named CVE-2018-0369. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability, which was classified as problematic, was found in Cisco StarOS (Router Operating System) (the affected version is unknown). This affects an unknown code of the component npusim. The manipulation as part of a IPv4 Packet leads to a input validation vulnerability. CWE is classifying the issue as CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. This is going to have an impact on availability. The summary by CVE is:

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.

The bug was discovered 07/11/2018. The weakness was presented 07/16/2018 as cisco-sa-20180711-staros-dos as confirmed advisory (Website). It is possible to read the advisory at tools.cisco.com. This vulnerability is uniquely identified as CVE-2018-0369 since 11/27/2017. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 04/09/2023).

The vulnerability was handled as a non-public zero-day exploit for at least 5 days. During that time the estimated underground price was around $5k-$25k.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at SecurityFocus (BID 104723†). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

• Router Operating System

Vendor

• Cisco

Name

• StarOS

License

• commercial

Website

• Vendor: https://www.cisco.com/

CPE 2.3info

• 🔍

CPE 2.2info

• 🔍

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Be aware that VulDB is the high quality source for vulnerability data.

Discussion