CVE-2021-1513 | Cisco SD-WAN Software vDaemon Denial of Service Vulnerability

A vulnerability in the vDaemon process of Cisco SD-WAN Software could allow an unauthenticated, remote attacker to cause a device to reload, resulting in a denial of service (DoS) condition. This vulnerability is due to insufficient handling of malformed packets. An attacker could exploit this vulnerability by sending crafted traffic to an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

Published: 2021-05-06 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-1513 is rated Moderate Risk (55.6/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.52%). Review affected assets and schedule remediation.

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-2021-1513

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 0.82% 1.52% +0.70%
2 2025-11-21 0.60% 0.82% +0.22%
3 2025-11-18 — 0.60% —

Full EPSS history (14 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-1513

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
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:N)
No account or special rights needed—anonymous or random user is enough.
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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
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:N)
No account or special rights needed—anonymous or random user is enough.
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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]
7.8 2.0 HIGH
AV:N/AC:L/Au:N/C:N/I:N/A:C Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:C)
Complete availability impact.
 10.0 6.9 [email protected]

Weakness enumeration for CVE-2021-1513

Affected software / configurations for CVE-2021-1513

Vendor Product Version Raw CPE
cisco catalyst_sd-wan_manager < 20.3.1 cpe:2.3:a:cisco:catalyst_sd-wan_manager:*:*:*:*:*:*:*:*
cisco catalyst_sd-wan_manager >= 20.4, < 20.4.1 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 — cpe:2.3:a:cisco:sd-wan_vbond_orchestrator:-:*:*:*:*:*:*:*
cisco vsmart_controller_firmware — cpe:2.3:o:cisco:vsmart_controller_firmware:-:*:*:*:*:*:*:*
cisco vedge_100_firmware — cpe:2.3:o:cisco:vedge_100_firmware:-:*:*:*:*:*:*:*
cisco vedge_1000_firmware — cpe:2.3:o:cisco:vedge_1000_firmware:-:*:*:*:*:*:*:*
cisco vedge_100b_firmware — cpe:2.3:o:cisco:vedge_100b_firmware:-:*:*:*:*:*:*:*
cisco vedge_100m_firmware — cpe:2.3:o:cisco:vedge_100m_firmware:-:*:*:*:*:*:*:*
cisco vedge_100wm_firmware — cpe:2.3:o:cisco:vedge_100wm_firmware:-:*:*:*:*:*:*:*
cisco vedge_2000_firmware — cpe:2.3:o:cisco:vedge_2000_firmware:-:*:*:*:*:*:*:*
cisco vedge_5000_firmware — cpe:2.3:o:cisco:vedge_5000_firmware:-:*:*:*:*:*:*:*
cisco vedge-100b_firmware — cpe:2.3:o:cisco:vedge-100b_firmware:-:*:*:*:*:*:*:*
cisco vedge_cloud_firmware — cpe:2.3:o:cisco:vedge_cloud_firmware:-:*:*:*:*:*:*:*

References for CVE-2021-1513

cvelogic Threat Intelligence