CVE-2021-1520
CVE-2021-1520 is a medium-severity vulnerability in Cisco Rv340 Firmware with a CVSS 3.x base score of 6.7. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-123.
Key facts
- Severity: Medium (CVSS 3.x base score 6.7)
- CVSS v2: 7.2
- EPSS exploit prediction: 0% (21st percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-123
- Affected product: Cisco Rv340 Firmware
- Published:
- Last modified:
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.
Frequently asked questions
- What is CVE-2021-1520?
- 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.
- How severe is CVE-2021-1520?
- CVE-2021-1520 has a CVSS 3.x base score of 6.7, rated medium severity. It is exploitable over local access with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
- Is CVE-2021-1520 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (21st percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2021-1520?
- CVE-2021-1520 primarily affects Cisco Rv340 Firmware. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2021-1520?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- When was CVE-2021-1520 published?
- CVE-2021-1520 was published on 2021-05-06 and last updated on 2026-06-17.
References
Affected products (4)
- cpe:2.3:o:cisco:rv340_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:cisco:rv340w_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:cisco:rv345_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:cisco:rv345p_firmware:*:*:*:*:*:*:*:*
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