Headline
CVE-2021-40114: Cisco Security Advisory: Multiple Cisco Products Snort Memory Leak Denial of Service Vulnerability
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.
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.
Fixed Releases
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.
1. Cisco FMC and FTD Software releases 6.2.2 and earlier, as well as releases 6.3.0 and 6.5.0, have reached end of software maintenance. Customers are advised to migrate to a supported release that includes the fix for this vulnerability.
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.
Related news
Debian Linux Security Advisory 5354-1 - Multiple security vulnerabilities were discovered in snort, a flexible Network Intrusion Detection System, which could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition or bypass filtering technology on an affected device and ex-filtrate data from a compromised host.