---
id: CVE-2021-1612
title: Cisco IOS XE SD-WAN Arbitrary File Overwrite Vulnerability
summary: "A vulnerability in the Cisco IOS XE SD-WAN Software CLI could allow an authenticated, local attacker to overwrite arbitrary files on the local system.\r\n\r\nThis vulnerability is due to improper access controls on files within the local file …"
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N'
cvssSource: vendor
vendor: Cisco
product: Cisco 4000 Series Integrated Services Routers
affected:
  - 1000_series_integrated_services_routers
  - asr_1000_series_aggregation_services_routers
  - 4000_series_integrated_services_routers
  - integrated_services_virtual_router
  - cloud_services_router_1000v_series
  - catalyst_ir1100_rugged_series_routers
published: '2021-09-22'
updated: '2021-09-22'
sourceUpdated: '2021-09-22T16:00:00+00:00'
source: CSAF
sourceUrl: >-
  https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sd-wan-GjR5pGOm
references:
  - url: >-
      https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sd-wan-GjR5pGOm
  - url: 'https://software.cisco.com'
tags:
  - csaf
  - vendor-advisory
  - cisco
epss: 0.0025
epssPercentile: 0.14676
ingestedAt: '2026-09-25T07:41:37.788Z'
---

## Overview

A vulnerability in the Cisco IOS XE SD-WAN Software CLI could allow an authenticated, local attacker to overwrite arbitrary files on the local system.

This vulnerability is due to improper access controls on files within the local file system. An attacker could exploit this vulnerability by placing a symbolic link in a specific location on the local file system. A successful exploit could allow the attacker to overwrite arbitrary files on an affected device.

Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.



This advisory is part of the September 2021 release of the Cisco IOS and IOS XE Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see Cisco Event Response: September 2021 Semiannual Cisco IOS and IOS XE Software Security Advisory Bundled Publication. ["https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-74581"]

## Vendor advisories

- **cisco-sa-sd-wan-GjR5pGOm** · Cisco · affected: Cisco 1000 Series Integrated Services Routers, Cisco ASR 1000 Series Aggregation Services Routers, Cisco 4000 Series Integrated Services Routers, Cisco Integrated Services Virtual Router, Cisco Cloud Services Router 1000V Series, Cisco Catalyst IR1100 Rugged Series Routers · updated 2021-09-22 · [advisory](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sd-wan-GjR5pGOm)

**Cisco IOS XE SD-WAN Software Arbitrary File Overwrite Vulnerability**. Released 2021-09-22.

Affected:

- Cisco 1000 Series Integrated Services Routers
- Cisco ASR 1000 Series Aggregation Services Routers
- Cisco 4000 Series Integrated Services Routers
- Cisco Integrated Services Virtual Router
- Cisco Cloud Services Router 1000V Series
- Cisco Catalyst IR1100 Rugged Series Routers

## Remediation

Cisco has released software updates that address this vulnerability. https://software.cisco.com