CVE intelligence and bounded remediation

CVE-2017-6627 — Cisco IOS Software and Cisco IOS XE Software UDP Packet Processing Denial-of-Service Vulnerability

High CVSS 7.5 CISA KEV

A vulnerability in the UDP processing code of Cisco IOS 15.1, 15.2, and 15.4 and IOS XE 3.14 through 3.18 could allow an unauthenticated, remote attacker to cause the input queue of an affected system to hold UDP packets, causing an interface queue wedge and a denial of service (DoS) condition. The vulnerability is due to Cisco IOS Software application changes that create UDP sockets and leave the sockets idle without closing them. An attacker could exploit this vulnerability by sending UDP packets with a destination port of 0 to an affected device. A successful exploit could allow the attacker to cause UDP packets to be held in the input interfaces queue, resulting in a DoS condition. The input interface queue will stop holding UDP packets when it receives 250 packets. Cisco Bug IDs: CSCup10024, CSCva55744, CSCva95506.

Severity
High
CVSS
7.5 (3.1)
Published
2017-09-07
CISA KEV
Known exploited
Ecosystem
operating-system
Weaknesses
CWE-399, CWE-404

Affected products

  • cisco / ios / 15.1(2)gc
  • cisco / ios / 15.1(2)gc1
  • cisco / ios / 15.1(2)gc2
  • cisco / ios / 15.1(4)gc
  • cisco / ios / 15.1(4)gc1
  • cisco / ios / 15.1(4)gc2

Showing 6 representative product identities from 71 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

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