CVE intelligence and bounded remediation

CVE-2020-3235 — Cisco Ios security vulnerability

High CVSS 7.7

A vulnerability in the Simple Network Management Protocol (SNMP) subsystem of Cisco IOS Software and Cisco IOS XE Software on Catalyst 4500 Series Switches could allow an authenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to insufficient input validation when the software processes specific SNMP object identifiers. An attacker could exploit this vulnerability by sending a crafted SNMP packet to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. Note: To exploit this vulnerability by using SNMPv2c or earlier, the attacker must know the SNMP read-only community string for an affected system. To exploit this vulnerability by using SNMPv3, the attacker must know the user credentials for the affected system.

Severity
High
CVSS
7.7 (3.1)
Published
2020-06-03
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-118, CWE-20

Affected products

  • cisco / ios / 12.2(52)sg
  • cisco / ios / 12.2(53)sg1
  • cisco / ios / 12.2(53)sg2
  • cisco / ios / 12.2(53)sg3
  • cisco / ios / 12.2(53)sg4
  • cisco / ios / 12.2(53)sg5

Showing 6 representative product identities from 151 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Resource exhaustion and denial of service

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Identify attacker-influenced work factors including input size, nesting, compression, fan-out, regex cost, allocation, recursion, retries, and connection lifetime.
  • Map per-request and shared CPU, memory, disk, descriptor, thread, queue, and downstream-service limits.
  • Determine whether authentication, tenancy, quotas, and rate controls apply before expensive processing begins.

Remediate safely

  • Bound input size, nesting, expansion, work, concurrency, queue depth, retries, and execution time before resource-intensive processing.
  • Release resources on every success, error, cancellation, and timeout path and use backpressure instead of unbounded buffering.
  • Update affected components and add small deterministic tests that assert resource ceilings rather than exhausting a host.

Authoritative sources

Complete CVE record and remediation plan

The detailed catalog view below loads this exact record, its source evidence, and the full seven-phase agentic change plan.