CVE intelligence and bounded remediation

CVE-2025-20155 — Cisco Ios Xe security vulnerability

Medium CVSS 6

A vulnerability in the bootstrap loading of Cisco IOS XE Software could allow an authenticated, local attacker to write arbitrary files to an affected system. This vulnerability is due to insufficient input validation of the bootstrap file that is read by the system software when a device is first deployed in SD-WAN mode or when an administrator configures SD-Routing on the device. An attacker could exploit this vulnerability by modifying a bootstrap file generated by Cisco Catalyst SD-WAN Manager, loading it into the device flash, and then either reloading the device in a green field deployment in SD-WAN mode or configuring the device with SD-Routing. A successful exploit could allow the attacker to perform arbitrary file writes to the underlying operating system.

Severity
Medium
CVSS
6 (3.1)
Published
2025-05-07
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-1287

Affected products

  • cisco / ios_xe / 17.9.4
  • cisco / ios_xe / 17.9.4a
  • cisco / ios_xe / 17.9.5
  • cisco / ios_xe / 17.9.5a
  • cisco / ios_xe / 17.9.5b
  • cisco / ios_xe / 17.9.5e

Showing 6 representative product identities from 28 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Path traversal, unsafe upload, and file handling

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

Check exposure

  • Trace untrusted filenames, archive entries, URLs, and path segments into read, write, include, extraction, and upload operations.
  • Identify filesystem roots, mount permissions, symbolic-link behavior, archive handling, and whether uploaded content is web-accessible or executable.
  • Review canonicalization and containment checks across supported operating systems and storage backends.

Remediate safely

  • Generate server-side storage identifiers and resolve paths beneath a fixed root using filesystem-aware containment checks.
  • Reject absolute, parent-relative, alternate-separator, device, link, and archive entries that escape the intended root.
  • Store uploads outside executable or served paths, validate type and size, and use private atomic temporary files.

Authoritative sources

Complete CVE record and remediation plan

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