Multiple Cisco products are affected by a vulnerability in the way the Snort detection engine processes ICMP traffic that could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper memory resource management while the Snort detection engine is processing ICMP packets. An attacker could exploit this vulnerability by sending a series of ICMP packets through an affected device. A successful exploit could allow the attacker to exhaust resources on the affected device, causing the device to reload. 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-snort-dos-s2R7W9UU This advisory is part of the October 2021 release of the Cisco ASA, FTD, and FMC Security Advisory Bundled publication. For a complete list of the advisories and links to them, see Cisco Event Response: October 2021 Cisco ASA, FMC, and FTD Software Security Advisory Bundled Publication.
Multiple Cisco products are affected by a vulnerability in the way the Snort detection engine processes ICMP traffic that could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.
The vulnerability is due to improper memory resource management while the Snort detection engine is processing ICMP packets. An attacker could exploit this vulnerability by sending a series of ICMP packets through an affected device. A successful exploit could allow the attacker to exhaust resources on the affected device, causing the device to reload.
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-snort-dos-s2R7W9UU
This advisory is part of the October 2021 release of the Cisco ASA, FTD, and FMC Security Advisory Bundled publication. For a complete list of the advisories and links to them, see Cisco Event Response: October 2021 Cisco ASA, FMC, and FTD Software Security Advisory Bundled Publication.
At the time of publication, this vulnerability affected all open source Snort project releases earlier than Release 2.9.18. For more information on open source Snort, see the Snort website.
At the time of publication, this vulnerability affected the following Cisco products if they were running a vulnerable release of Cisco Software:
At the time of publication, this vulnerability affected the following Cisco products if they were running a release earlier than the first fixed release of Cisco Unified Threat Defense (UTD) Snort Intrusion Prevention System (IPS) Engine for Cisco IOS XE Software or Cisco UTD Engine for Cisco IOS XE SD-WAN Software.
Note: UTD is not installed on these devices by default:
For information about which Cisco software releases were vulnerable at the time of publication, see the Fixed Software section of this advisory. See the Details section in the bug ID(s) at the top of this advisory for the most complete and current information.
Only products listed in the Vulnerable Products section of this advisory are known to be affected by this vulnerability.
Cisco has confirmed that this vulnerability does not affect the following Cisco products:
There are no workarounds that address this vulnerability.
When considering software upgrades, customers are advised to regularly consult the advisories for Cisco products, which are available from the Cisco Security Advisories 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.
At the time of publication, the release information in the following table(s) was accurate. See the Details section in the bug ID(s) at the top of this advisory for the most complete and current information.
The left column lists Cisco software releases, and the right column indicates whether a release was affected by the vulnerability described in this advisory and which release included the fix for this vulnerability.
Cisco FTD Software
| FTD Software Release | First Fixed Release for This Vulnerability |
|---|---|
| 6.2.2 and earlier1 | Migrate to a fixed release. |
| 6.2.3 | Migrate to a fixed release. |
| 6.3.01 | Migrate to a fixed release. |
| 6.4.0 | 6.4.0.12 |
| 6.5.01 | Migrate to a fixed release. |
| 6.6.0 | 6.6.3 |
| 6.7.0 | 6.7.0.2 |
| 7.0.0 | Not vulnerable. |
For instructions on upgrading your FTD device, see Cisco Firepower Management Center Upgrade Guide.
Cisco UTD Software
| UTD Software Release | First Fixed Release for This Vulnerability |
|---|---|
| 16.12 | 16.12.6 |
| 17.3 | 17.3.4a |
| 17.4 | 17.4.2 |
| 17.5 | Not vulnerable. |
| 17.6 | Not vulnerable. |
| 17.7 | Not vulnerable. |
Snort Software Release
| Snort Major Release | First Fixed Release for This Vulnerability |
|---|---|
| 2.x | 2.9.18 |
| 3.x | Not vulnerable. |
The Cisco Product Security Incident Response Team (PSIRT) validates only the affected and fixed release information that is documented in this advisory.
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 by Santosh Krishnamurthy of Cisco 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 |
|---|---|---|---|---|
| 1.1 | Updated the Source section. | Source | Final | 2021-OCT-29 |
| 1.0 | Initial public release. | - | Final | 2021-OCT-27 |
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