CVE-2021-1509 [High] | Memory Corruption in Vedge 100 Firmware

Multiple vulnerabilities in Cisco SD-WAN vEdge Software could allow an attacker to execute arbitrary code as the root user or cause a denial of service (DoS) condition on an affected device. For more information about these vulnerabilities, see the Details section of this advisory.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	0.86%	1.22%	+0.36%
2	2025-03-30	2.57%	0.86%	-1.71%
3	2025-03-29	—	2.57%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

0.86%

1.22%

+0.36%

2025-03-30

2.57%

0.86%

-1.71%

2025-03-29

—

2.57%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
7.5	3.1	HIGH	`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/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:H) Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work. 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.	1.6	5.9	[email protected]
7.5	3.1	HIGH	`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/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:H) Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work. 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.	1.6	5.9	[email protected]
8.5	2.0	HIGH	`AV:N/AC:M/Au:S/C:C/I:C/A:C` Click to expand Access vector (AV:N) Can be exploited remotely over network reachability. Access complexity (AC:M) Exploitation needs some favorable conditions, but not exceptional ones. Authentication (AU:S) A single authentication is required. Confidentiality impact (C:C) Complete confidentiality impact. Integrity impact (I:C) Complete integrity impact. Availability impact (A:C) Complete availability impact.	6.8	10.0	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

7.5

3.1

HIGH

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/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:H): Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
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.

1.6

5.9

[email protected]

7.5

3.1

HIGH

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/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:H): Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
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.

1.6

5.9

[email protected]

8.5

2.0

HIGH

AV:N/AC:M/Au:S/C:C/I:C/A:C Click to expand

Access vector (AV:N): Can be exploited remotely over network reachability.
Access complexity (AC:M): Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:S): A single authentication is required.
Confidentiality impact (C:C): Complete confidentiality impact.
Integrity impact (I:C): Complete integrity impact.
Availability impact (A:C): Complete availability impact.

6.8

10.0

[email protected]

Affected software / configurations for CVE-2021-1509

Vendor	Product	Version	Raw CPE
cisco	vedge_100_firmware	>= 20.4, < 20.4.1	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_100_firmware	19.2.99	cpe:2.3:o:cisco:vedge_100_firmware:19.2.99:::::::*
cisco	vedge_1000_firmware	>= 20.4, < 20.4.1	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_1000_firmware	19.2.99	cpe:2.3:o:cisco:vedge_1000_firmware:19.2.99:::::::*
cisco	vedge_100b_firmware	>= 20.4, < 20.4.1	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_100b_firmware	19.2.99	cpe:2.3:o:cisco:vedge_100b_firmware:19.2.99:::::::*
cisco	vedge_100m_firmware	>= 20.4, < 20.4.1	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_100m_firmware	19.2.99	cpe:2.3:o:cisco:vedge_100m_firmware:19.2.99:::::::*
cisco	vedge_100wm_firmware	>= 20.4, < 20.4.1	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_100wm_firmware	19.2.99	cpe:2.3:o:cisco:vedge_100wm_firmware:19.2.99:::::::*
cisco	vedge_2000_firmware	>= 20.4, < 20.4.1	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_2000_firmware	19.2.99	cpe:2.3:o:cisco:vedge_2000_firmware:19.2.99:::::::*
cisco	vedge_5000_firmware	>= 20.4, < 20.4.1	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_5000_firmware	19.2.99	cpe:2.3:o:cisco:vedge_5000_firmware:19.2.99:::::::*
cisco	vedge_cloud_firmware	>= 20.4, < 20.4.1	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::::::::
cisco	vedge_cloud_firmware	19.2.99	cpe:2.3:o:cisco:vedge_cloud_firmware:19.2.99:::::::*

References for CVE-2021-1509

URL	Tags
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-buffover-MWGucjtO	Vendor Advisory

URL

CVE-2021-1509 | Cisco SD-WAN vEdge Software Buffer Overflow Vulnerabilities

Exploit prediction scoring system (EPSS) score for CVE-2021-1509

Common vulnerability scoring system (CVSS) metrics for CVE-2021-1509

Weakness enumeration for CVE-2021-1509

Affected software / configurations for CVE-2021-1509

References for CVE-2021-1509