CVE-2021-34723
mediumpriority · track · 27EPSS 0.002 · 16 %ileEURUUSEPSS · scored 2026-10-27
A vulnerability in a specific CLI command that is run on Cisco IOS XE SD-WAN Software could allow an authenticated, local attacker to overwrite arbitrary files in the configuration database of an affected device. This vulnerability is due to insufficient validation of specific CLI command parameters. An attacker could exploit this vulnerability by issuing that command with specific parameters. A successful exploit could allow the attacker to overwrite the content of the configuration database and gain root-level access to an affected device.
remediations
Vendor fix, mitigation, or workaround guidance, as published by each source.
A vendor fix is available.
- Fixed17.11.99SWcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - Fixed17.2.1cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - Fixed17.2.1acisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - Fixed17.2.1rcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - Fixed17.2.1vcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - Fixed17.2.2cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - Fixed17.2.3cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - Fixed17.3.1cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - Fixed17.3.1acisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - Fixed17.3.1wcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - Fixed17.3.1xcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - Fixed17.3.1zcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - Fixed17.3.2cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - Fixed17.3.2acisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - Fixed17.4.1cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - Fixed17.4.1acisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - Fixed17.4.1bcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - Fixed17.4.1ccisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco IOS XE Catalyst SD-WANcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (22)
Products and version ranges known to be affected.
advisories (1)
Vendor and ecosystem advisories describing this.
- cisco-sa-iosxesdwan-arbfileov-MVOF3ZZnCisco IOS XE SD-WAN Software Arbitrary File Overwrite Vulnerability2021-09-22csaf · cisco_csafUS
A vulnerability in a specific CLI command that is run on Cisco IOS XE SD-WAN Software could allow an authenticated, local attacker to overwrite arbitrary files in the configuration database of an affected device. This vulnerability is due to insufficient validation of specific CLI command parameters. An attacker could exploit this vulnerability by issuing that command with specific parameters. A successful exploit could allow the attacker to overwrite the content of the configuration database and gain root-level access to 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"]
also known as (4)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (6)
External citations — patches, advisories, analysis.
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxesdwan-arbfileov-MVOF3ZZncnnvd
- https://vigilance.fr/vulnerability/Cisco-IOS-XE-SD-WAN-Software-file-write-via-CLI-Command-Parameters-36501cnnvd
- https://www.auscert.org.au/bulletins/ESB-2021.3179cnnvd
- https://www.cybersecurity-help.cz/vdb/SB2021092413cnnvd
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxesdwan-arbfileov-MVOF3ZZnenisa_euvd
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxesdwan-arbfileov-MVOF3ZZnVendor Advisorynvd
Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.
Free scan