CVE-2021-1164Network attack vector

Root code execution or reload via UPnP overflow

Published Jan 13, 2021 · Updated Nov 12, 2024

A stack-based buffer overflow in Cisco Small Business RV110W, RV130, RV130W, and RV215W UPnP services allows remote attackers to execute root code. The UPnP service improperly validates incoming traffic, allowing a crafted request to overwrite its stack buffer and redirect execution or reload the device. Network reachability is sufficient; no authentication or user action is required, and the outcomes are bounded to root-level code execution or a device reload.

CVSS severity9.8
Critical
EPSS probability2.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A stack-based buffer overflow in Cisco Small Business RV110W, RV130, RV130W, and RV215W UPnP services allows remote attackers to execute root code. The UPnP service improperly validates incoming traffic, allowing a crafted request to overwrite its stack buffer and redirect execution or reload the device. Network reachability is sufficient; no authentication or user action is required, and the outcomes are bounded to root-level code execution or a device reload.

The record

CVE
CVE-2021-1164
Published
Jan 13, 2021
Updated
Nov 12, 2024
Vendor
ClamAV
Product
Cisco Small Business RV Series Router Firmware
Classifications
CWE-787, CWE-121
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 13, 2021CVE publishedPublication date reported by the CVE source.
  2. Nov 12, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=n/a

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ClamAV · Cisco Small Business RV Series Router Firmwareversion=n/a

Published CVSS scores

9.0NISTAV:N/AC:L/Au:S/C:C/I:C/A:C
9.8Cisco Systems, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
CWE-121Stack-based Buffer Overflow

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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