A vulnerability in the rate limiter for Bidirectional Forwarding Detection (BFD) traffic of…
CVE-2022-20623 is a high-severity vulnerability in Cisco NX-OS Software from Cisco, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. There is no confirmed exploitation so far. EPSS estimates a 11.9% chance of exploitation within 30 days, which is in the top 3.84% of all scored CVEs.
EPSS places it among the vulnerabilities most likely to be exploited soon.
What to do
- Check which version of Cisco NX-OS Software you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on tools.cisco.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Cisco | Cisco NX-OS Software | Not specified in the record | Not stated |
| Cisco | Nx-os | 7.0\(3\)i6\(2\) through 7.0\(3\)i7\(3\); 7.0\(3\)i6\(2\) through 9.3\(8\); 10.1\(1\) through 10.2\(1\) | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.6 | High | CNA (cisco.com) |
| CVSS 3.1 | 7.5 | High | NVD |
| CVSS 2.0 | 7.1 | High | NVD |
Official description
A vulnerability in the rate limiter for Bidirectional Forwarding Detection (BFD) traffic of Cisco NX-OS Software for Cisco Nexus 9000 Series Switches could allow an unauthenticated, remote attacker to cause BFD traffic to be dropped on an affected device. This vulnerability is due to a logic error in the BFD rate limiter functionality. An attacker could exploit this vulnerability by sending a crafted stream of traffic through the device. A successful exploit could allow the attacker to cause BFD traffic to be dropped, resulting in BFD session flaps. BFD session flaps can cause route instability and dropped traffic, resulting in a denial of service (DoS) condition. This vulnerability applies to both IPv4 and IPv6 traffic.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
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