CVE-2021-1520

Cisco RV340, RV340W, RV345, and RV345P Dual WAN Gigabit VPN Routers Local Privilege Escalation Vulnerability

MEDIUM
6.7
CVSS Score
Published: May 6, 2021 at 12:51 PM UTC
Updated: June 17, 2026 at 03:31 AM UTC
9 products affected across 1 vendorRV340W FirmwareRV345 FirmwareRV345P Firmware

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Severity
MEDIUM6.7
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

Description

A vulnerability in the internal message processing of Cisco RV340, RV340W, RV345, and RV345P Dual WAN Gigabit VPN Routers could allow an authenticated, local attacker to run arbitrary commands with root privileges on the underlying operating system (OS). This vulnerability exists because an internal messaging service does not properly sanitize input. An attacker could exploit this vulnerability by first authenticating to the device and then sending a crafted request to the internal service. A successful exploit could allow the attacker to run arbitrary commands with root privileges on the underlying OS. To exploit this vulnerability, the attacker must have valid Administrator credentials for the device.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 1.0.03.21
Affected range stops below 1.0.03.21, so it looks safe — our inference, not a vendor statement
cisco-rv340 (same device)
v < 1.0.03.21
Affected range stops below 1.0.03.21, so it looks safe — our inference, not a vendor statement
cisco-rv340w (same device)
v < 1.0.03.21
Affected range stops below 1.0.03.21, so it looks safe — our inference, not a vendor statement
cisco-rv345 (same device)
v < 1.0.03.21
Affected range stops below 1.0.03.21, so it looks safe — our inference, not a vendor statement
cisco-rv345p (same device)
80%
All versions
All versions
80%
All versions
All versions

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

6.7MEDIUMcisco
Attack Vector
LOCAL
Complexity
LOW
Privileges
HIGH
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-123

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