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Fencer Vulns
medium 6.7

CVE-2021-34726 json

Cisco SD-WAN Software Command Injection Vulnerability

published 2021-09-23 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-21376

cvss
6.7
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 30%
public exploits
0
none known

Summary

A vulnerability in the CLI of Cisco SD-WAN Software could allow an authenticated, local attacker to inject arbitrary commands to be executed with root-level privileges on the underlying operating system of an affected device. This vulnerability is due to insufficient input validation on certain CLI commands. An attacker could exploit this vulnerability by authenticating to an affected device and submitting crafted input to the CLI. The attacker must be authenticated as an administrative user to execute the affected commands. A successful exploit could allow the attacker to execute commands with root-level privileges.

Patch / fix

  • cisco sd-wan 18.4.6, 19.2.3, 20.1.2, 20.3.1, 20.4.1, 20.5.1

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
2 y ago

Exploit prediction

0.37% chance of exploitation in the next 30 days, higher than 30% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.0 6.7 CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 6.7 CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.2 AV:L/AC:L/Au:N/C:C/I:C/A:C

Affected products

  • Cisco Cisco SD-WAN Solution

Classification

Weakness
  • CWE-77 Improper Neutralization of Special Elements used in a Command
  • CWE-78 Improper Neutralization of Special Elements used in an OS Command

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.