A vulnerability in the Protocol Independent Multicast (PIM) feature of Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause the PIM process to restart, resulting in a denial of service condition on an affected device. The vulnerability is due to the incorrect processing of crafted AutoRP packets. An attacker could exploit this vulnerability by sending crafted packets to port UDP 496 on a reachable IP address on the device. A successful exploit could allow the attacker to cause the PIM process to restart. There are workarounds that address this vulnerability. This advisory is available at the following link: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190417-iosxr-pim-dos
A vulnerability in the Protocol Independent Multicast (PIM) feature of Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause the PIM process to restart, resulting in a denial of service condition on an affected device.
The vulnerability is due to the incorrect processing of crafted AutoRP packets. An attacker could exploit this vulnerability by sending crafted packets to port UDP 496 on a reachable IP address on the device. A successful exploit could allow the attacker to cause the PIM process to restart.
There are workarounds that address this vulnerability.
This advisory is available at the following link:
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190417-iosxr-pim-dos
Only products listed in the Vulnerable Products section of this advisory are known to be affected by this vulnerability.
In environments that do not require PIM rendezvous point mappings learned through Auto-RP, administrators can disable the feature with the auto-rp listen disable configuration command as shown in the following example:
Vulmon
router pim
address-family ipv4
auto-rp listen disable
After the configuration has been committed, a restart of the PIM process is required to disable the listening on UDP port 496. The PIM process can be restarted via the process restart pim location all CLI command.For information about fixed software releases, consult the Cisco bug ID(s) at the top of this advisory.
When considering software upgrades, customers are advised to regularly consult the advisories for Cisco products, which are available from the Cisco Security Advisories and Alerts page, to determine exposure and a complete upgrade solution.
In all cases, customers should ensure that the devices to be upgraded contain sufficient memory and confirm that current hardware and software configurations will continue to be supported properly by the new release. If the information is not clear, customers are advised to contact the Cisco Technical Assistance Center (TAC) or their contracted maintenance providers.
The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.
This vulnerability was found during internal security testing.
To learn about Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy. This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco.
| Version | Description | Section | Status | Date |
|---|---|---|---|---|
| 1.2 | Added 'location all' to 'process restart pim' command. | Workarounds | Final | 2019-June-28 |
| 1.1 | Added mitigation. | Workarounds | Final | 2019-May-03 |
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