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Fencer Intel
medium 6.7

CVE-2021-1520 json

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

published 5y ago modified 4mo ago also EUVD-2021-6987

cvss
6.7
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 21%
public exploits
0
none known

Summary

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.

Patch / fix

  • cisco rv340_firmware 1.0.03.21
  • cisco rv340w_firmware 1.0.03.21
  • cisco rv345_firmware 1.0.03.21
  • cisco rv345p_firmware 1.0.03.21

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
2y ago

Exploit prediction

0.29% chance of exploitation in the next 30 days, higher than 21% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 6.7 CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 6.7 CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.2 AV:L/AC:L/Au:N/C:C/I:C/A:C

Affected products

  • Cisco Cisco Small Business RV Series Router Firmware

Classification

Weakness
  • CWE-123 Write-what-where Condition

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.