CVE-2021-1528 | Cisco SD-WAN Software Privilege Escalation Vulnerability

A vulnerability in the CLI of Cisco SD-WAN Software could allow an authenticated, local attacker to gain elevated privileges on an affected system. This vulnerability exists because the affected software does not properly restrict access to privileged processes. An attacker could exploit this vulnerability by invoking a privileged process in the affected system. A successful exploit could allow the attacker to perform actions with the privileges of the root user.

Published: 2021-06-04 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-1528 is rated Low Risk (36.9/100): CVSS High severity, with low exploitation likelihood (EPSS 0.25%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-1528

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.05% 0.25% +0.20%
2 2025-03-17 0.04% 0.05% +0.01%
3 2023-03-07 — 0.04% —

Full EPSS history (7 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-1528

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.9 [email protected]
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.9 [email protected]
7.2 2.0 HIGH
AV:L/AC:L/Au:N/C:C/I:C/A:C Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
 3.9 10.0 [email protected]

Weakness enumeration for CVE-2021-1528

Affected software / configurations for CVE-2021-1528

Vendor Product Version Raw CPE
cisco catalyst_sd-wan_manager >= 20.4, < 20.4.2 cpe:2.3:a:cisco:catalyst_sd-wan_manager:*:*:*:*:*:*:*:*
cisco catalyst_sd-wan_manager >= 20.5, < 20.5.1 cpe:2.3:a:cisco:catalyst_sd-wan_manager:*:*:*:*:*:*:*:*
cisco sd-wan_vbond_orchestrator >= 20.4, < 20.4.2 cpe:2.3:a:cisco:sd-wan_vbond_orchestrator:*:*:*:*:*:*:*:*
cisco sd-wan_vbond_orchestrator >= 20.5, < 20.5.1 cpe:2.3:a:cisco:sd-wan_vbond_orchestrator:*:*:*:*:*:*:*:*
cisco vsmart_controller >= 20.4, < 20.4.2 cpe:2.3:a:cisco:vsmart_controller:*:*:*:*:*:*:*:*
cisco vsmart_controller >= 20.5, < 20.5.1 cpe:2.3:a:cisco:vsmart_controller:*:*:*:*:*:*:*:*
cisco vedge_100_firmware >= 20.4, < 20.4.2 cpe:2.3:o:cisco:vedge_100_firmware:*:*:*:*:*:*:*:*
cisco vedge_100_firmware >= 20.5, < 20.5.1 cpe:2.3:o:cisco:vedge_100_firmware:*:*:*:*:*:*:*:*
cisco vedge_1000_firmware >= 20.4, < 20.4.2 cpe:2.3:o:cisco:vedge_1000_firmware:*:*:*:*:*:*:*:*
cisco vedge_1000_firmware >= 20.5, < 20.5.1 cpe:2.3:o:cisco:vedge_1000_firmware:*:*:*:*:*:*:*:*
cisco vedge_100b_firmware >= 20.4, < 20.4.2 cpe:2.3:o:cisco:vedge_100b_firmware:*:*:*:*:*:*:*:*
cisco vedge_100b_firmware >= 20.5, < 20.5.1 cpe:2.3:o:cisco:vedge_100b_firmware:*:*:*:*:*:*:*:*
cisco vedge_100m_firmware >= 20.4, < 20.4.2 cpe:2.3:o:cisco:vedge_100m_firmware:*:*:*:*:*:*:*:*
cisco vedge_100m_firmware >= 20.5, < 20.5.1 cpe:2.3:o:cisco:vedge_100m_firmware:*:*:*:*:*:*:*:*
cisco vedge_100wm_firmware >= 20.4, < 20.4.2 cpe:2.3:o:cisco:vedge_100wm_firmware:*:*:*:*:*:*:*:*
cisco vedge_100wm_firmware >= 20.5, < 20.5.1 cpe:2.3:o:cisco:vedge_100wm_firmware:*:*:*:*:*:*:*:*
cisco vedge_2000_firmware >= 20.4, < 20.4.2 cpe:2.3:o:cisco:vedge_2000_firmware:*:*:*:*:*:*:*:*
cisco vedge_2000_firmware >= 20.5, < 20.5.1 cpe:2.3:o:cisco:vedge_2000_firmware:*:*:*:*:*:*:*:*
cisco vedge_5000_firmware >= 20.4, < 20.4.2 cpe:2.3:o:cisco:vedge_5000_firmware:*:*:*:*:*:*:*:*
cisco vedge_5000_firmware >= 20.5, < 20.5.1 cpe:2.3:o:cisco:vedge_5000_firmware:*:*:*:*:*:*:*:*
cisco vedge_cloud_firmware >= 20.4, < 20.4.2 cpe:2.3:o:cisco:vedge_cloud_firmware:*:*:*:*:*:*:*:*
cisco vedge_cloud_firmware >= 20.5, < 20.5.1 cpe:2.3:o:cisco:vedge_cloud_firmware:*:*:*:*:*:*:*:*

References for CVE-2021-1528

cvelogic Threat Intelligence