CVE-2021-1309 [High] | Memory Corruption in Rv132w Firmware

Multiple vulnerabilities exist in the Link Layer Discovery Protocol (LLDP) implementation for Cisco Small Business RV Series Routers. An unauthenticated, adjacent attacker could execute arbitrary code or cause an affected router to leak system memory or reload. A memory leak or device reload would cause a denial of service (DoS) condition on an affected device. For more information about these vulnerabilities, see the Details section of this advisory. Note: LLDP is a Layer 2 protocol. To exploit these vulnerabilities, an attacker must be in the same broadcast domain as the affected device (Layer 2 adjacent).

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	0.11%	0.52%	+0.41%
2	2025-08-15	0.19%	0.11%	-0.09%
3	2025-03-30	—	0.19%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

0.11%

0.52%

+0.41%

2025-08-15

0.19%

0.11%

-0.09%

2025-03-30

—

0.19%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
7.4	3.1	HIGH	`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H` Click to expand Attack vector (AV:A) Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet. 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:C) Breaking this can reach past the original component and bite other resources—bigger blast radius. 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.	2.8	4.0	[email protected]
8.8	3.1	HIGH	`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H` Click to expand Attack vector (AV:A) Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet. 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: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.	2.8	5.9	[email protected]
8.3	2.0	HIGH	`AV:A/AC:L/Au:N/C:C/I:C/A:C` Click to expand Access vector (AV:A) Requires access to an adjacent network segment. 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.	6.5	10.0	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

7.4

3.1

HIGH

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H Click to expand

Attack vector (AV:A): Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet.
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:C): Breaking this can reach past the original component and bite other resources—bigger blast radius.
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.

2.8

4.0

[email protected]

8.8

3.1

HIGH

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

Attack vector (AV:A): Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet.
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: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.

2.8

5.9

[email protected]

8.3

2.0

HIGH

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

Access vector (AV:A): Requires access to an adjacent network segment.
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.

6.5

10.0

[email protected]

Affected software / configurations for CVE-2021-1309

Vendor	Product	Version	Raw CPE
cisco	rv132w_firmware	1.0.0.14	cpe:2.3:o:cisco:rv132w_firmware:1.0.0.14:::::::*
cisco	rv132w_firmware	1.0.1.14	cpe:2.3:o:cisco:rv132w_firmware:1.0.1.14:::::::*
cisco	rv132w_firmware	1.0.1.20	cpe:2.3:o:cisco:rv132w_firmware:1.0.1.20:::::::*
cisco	rv134w_firmware	1.0.0.14	cpe:2.3:o:cisco:rv134w_firmware:1.0.0.14:::::::*
cisco	rv134w_firmware	1.0.1.14	cpe:2.3:o:cisco:rv134w_firmware:1.0.1.14:::::::*
cisco	rv134w_firmware	1.0.1.20	cpe:2.3:o:cisco:rv134w_firmware:1.0.1.20:::::::*
cisco	rv160_firmware	1.0.0.14	cpe:2.3:o:cisco:rv160_firmware:1.0.0.14:::::::*
cisco	rv160_firmware	1.0.1.14	cpe:2.3:o:cisco:rv160_firmware:1.0.1.14:::::::*
cisco	rv160_firmware	1.0.1.20	cpe:2.3:o:cisco:rv160_firmware:1.0.1.20:::::::*
cisco	rv160w_firmware	1.0.0.14	cpe:2.3:o:cisco:rv160w_firmware:1.0.0.14:::::::*
cisco	rv160w_firmware	1.0.1.14	cpe:2.3:o:cisco:rv160w_firmware:1.0.1.14:::::::*
cisco	rv160w_firmware	1.0.1.20	cpe:2.3:o:cisco:rv160w_firmware:1.0.1.20:::::::*
cisco	rv260_firmware	1.0.0.14	cpe:2.3:o:cisco:rv260_firmware:1.0.0.14:::::::*
cisco	rv260_firmware	1.0.1.14	cpe:2.3:o:cisco:rv260_firmware:1.0.1.14:::::::*
cisco	rv260_firmware	1.0.1.20	cpe:2.3:o:cisco:rv260_firmware:1.0.1.20:::::::*
cisco	rv260p_firmware	1.0.0.14	cpe:2.3:o:cisco:rv260p_firmware:1.0.0.14:::::::*
cisco	rv260p_firmware	1.0.1.14	cpe:2.3:o:cisco:rv260p_firmware:1.0.1.14:::::::*
cisco	rv260p_firmware	1.0.1.20	cpe:2.3:o:cisco:rv260p_firmware:1.0.1.20:::::::*
cisco	rv260w_firmware	1.0.0.14	cpe:2.3:o:cisco:rv260w_firmware:1.0.0.14:::::::*
cisco	rv260w_firmware	1.0.1.14	cpe:2.3:o:cisco:rv260w_firmware:1.0.1.14:::::::*
cisco	rv260w_firmware	1.0.1.20	cpe:2.3:o:cisco:rv260w_firmware:1.0.1.20:::::::*
cisco	rv340_firmware	1.0.0.14	cpe:2.3:o:cisco:rv340_firmware:1.0.0.14:::::::*
cisco	rv340_firmware	1.0.1.14	cpe:2.3:o:cisco:rv340_firmware:1.0.1.14:::::::*
cisco	rv340_firmware	1.0.1.20	cpe:2.3:o:cisco:rv340_firmware:1.0.1.20:::::::*
cisco	rv340w_firmware	1.0.0.14	cpe:2.3:o:cisco:rv340w_firmware:1.0.0.14:::::::*
cisco	rv340w_firmware	1.0.1.14	cpe:2.3:o:cisco:rv340w_firmware:1.0.1.14:::::::*
cisco	rv340w_firmware	1.0.1.20	cpe:2.3:o:cisco:rv340w_firmware:1.0.1.20:::::::*
cisco	rv345_firmware	1.0.0.14	cpe:2.3:o:cisco:rv345_firmware:1.0.0.14:::::::*
cisco	rv345_firmware	1.0.1.14	cpe:2.3:o:cisco:rv345_firmware:1.0.1.14:::::::*
cisco	rv345_firmware	1.0.1.20	cpe:2.3:o:cisco:rv345_firmware:1.0.1.20:::::::*
cisco	rv345p_firmware	1.0.0.14	cpe:2.3:o:cisco:rv345p_firmware:1.0.0.14:::::::*
cisco	rv345p_firmware	1.0.1.14	cpe:2.3:o:cisco:rv345p_firmware:1.0.1.14:::::::*
cisco	rv345p_firmware	1.0.1.20	cpe:2.3:o:cisco:rv345p_firmware:1.0.1.20:::::::*

References for CVE-2021-1309

URL	Tags
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-rv-multi-lldp-u7e4chCe	Vendor Advisory

URL

CVE-2021-1309 | Cisco Small Business RV Series Routers Link Layer Discovery Protocol Vulnerabilities

Exploit prediction scoring system (EPSS) score for CVE-2021-1309

Common vulnerability scoring system (CVSS) metrics for CVE-2021-1309

Weakness enumeration for CVE-2021-1309

Affected software / configurations for CVE-2021-1309

References for CVE-2021-1309