CVE-2021-34730

What it is

A vulnerability in the Universal Plug-and-Play (UPnP) service of Cisco Small Business RV110W, RV130, RV130W, and RV215W Routers could allow an unauthenticated, remote attacker to execute arbitrary code or cause an affected device to restart unexpectedly, resulting in a denial of service (DoS) condition. This vulnerability is due to improper validation of incoming UPnP traffic. An attacker could exploit this vulnerability by sending a crafted UPnP request to an affected device. A successful exploit could allow the attacker to execute arbitrary code as the root user on the underlying operating system or cause the device to reload, resulting in a DoS condition. Cisco has not released software updates that address this vulnerability.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data exposure, data tampering, service disruption.

Exploit odds

18.5% chance of exploitation in the next 30 days (EPSS). Higher than most.

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2021-06-15 00:00 UTC ReservedThe CVE id was reserved by its CNA
2. 2021-08-18 20:15 UTC PublishedDisclosed publicly on CVE.org and NVD
3. 2026-06-17 03:56 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 18.5% in the next 30 days (EPSS).
• Severity: 9.8 CRITICAL (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2021-08-18 20:15 UTC

Last modified

2026-06-17 03:56 UTC

Exploit probability

18.5% · EPSS, next 30 days

Weakness

CWE-121

Record status

Modified

Affected

• Cisco Application Extension Platform 1.0.3.55
• Cisco rv110w wireless-n Vpn Firewall Firmware
• Cisco rv130 Vpn Router Firmware
• Cisco rv130w wireless-n Multifunction Vpn Router Firmware
• Cisco rv215w wireless-n Vpn Router Firmware

Attack profile CVSS 3.1 · 9.8

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2021-34730.md and follow it. Check whether this project is affected by CVE-2021-34730. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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