Symptom
A vulnerability in the Zone-Based Firewall code of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause the device to reload.
The vulnerability is due to the way fragmented packets are handled in the firewall code. An attacker could exploit this vulnerability by sending fragmented IPv4 or IPv6 packets through the affected device. An exploit could allow the attacker to cause the device to crash, resulting in a denial of service (DoS) condition.
Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.
This advisory is available at the following link:
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180328-fwip
This advisory is part of the March 28, 2018, release of the Cisco IOS and IOS XE Software Security Advisory Bundled Publication, which includes 20 Cisco Security Advisories that describe 22 vulnerabilities. For a complete list of the advisories and links to them, see Cisco Event Response: March 2018 Semiannual Cisco IOS and IOS XE Software Security Advisory Bundled Publication.
Conditions
See Affected Products Section of the Advisory.
To determine whether a release is affected by any published Cisco Security Advisory, use the Cisco IOS Software Checker on Cisco.com at the following link: https://tools.cisco.com/security/center/softwarechecker.x
Workaround
There are no workarounds that address this vulnerability.
Further Problem Description
PSIRT Evaluation:
The Cisco PSIRT has assigned this bug the following CVSS version 3 score. The Base CVSS score as of the time of evaluation is 8.6:
https://tools.cisco.com/security/center/cvssCalculator.x?version=3.0&vector=CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:X/RL:X/RC:X
CVE ID CVE-2018-0157 has been assigned to document this issue.
Additional information on Cisco's security vulnerability policy can be found at the following URL:
http://www.cisco.com/en/US/products/products_security_vulnerability_policy.html
