CVE-2021-1572: A vulnerability in ConfD could allow an authenticated, local attacker to execute arbitrary commands at the level of the account under which ConfD is r...

Description

A vulnerability in ConfD could allow an authenticated, local attacker to execute arbitrary commands at the level of the account under which ConfD is running, which is commonly root. To exploit this vulnerability, an attacker must have a valid account on an affected device. The vulnerability exists because the affected software incorrectly runs the SFTP user service at the privilege level of the account that was running when the ConfD built-in Secure Shell (SSH) server for CLI was enabled. If the ConfD built-in SSH server was not enabled, the device is not affected by this vulnerability. An attacker with low-level privileges could exploit this vulnerability by authenticating to an affected device and issuing a series of commands at the SFTP interface. A successful exploit could allow the attacker to elevate privileges to the level of the account under which ConfD is running, which is commonly root. Note: Any user who can authenticate to the built-in SSH server may exploit this vulnerability. By default, all ConfD users have this access if the server is enabled. Software updates that address this vulnerability have been released.

Metrics

CVSS 3.1

7.8/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

0.25%

15.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Cisco	Confd	>= 7.4, <= 7.4.3
Cisco	Confd	>= 7.5, <= 7.5.2
Cisco	Network Services Orchestrator	>= 5.4, <= 5.4.3.1
Cisco	Network Services Orchestrator	>= 5.5, <= 5.5.2.2

References

Timeline

Published: Aug 4, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-1572?

A vulnerability in ConfD could allow an authenticated, local attacker to execute arbitrary commands at the level of the account under which ConfD is running, which is commonly root. To exploit this vulnerability, an attacker must have a valid account on an affected device. The vulnerability exists because the affected software incorrectly runs the SFTP user service at the privilege level of the account that was running when the ConfD built-in Secure Shell (SSH) server for CLI was enabled. If the ConfD built-in SSH server was not enabled, the device is not affected by this vulnerability. An attacker with low-level privileges could exploit this vulnerability by authenticating to an affected device and issuing a series of commands at the SFTP interface. A successful exploit could allow the attacker to elevate privileges to the level of the account under which ConfD is running, which is commonly root. Note: Any user who can authenticate to the built-in SSH server may exploit this vulnerability. By default, all ConfD users have this access if the server is enabled. Software updates that address this vulnerability have been released.

How severe is CVE-2021-1572?

CVE-2021-1572 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.25% probability of exploitation in the next 30 days.

How do I fix CVE-2021-1572?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.