CVE-2021-1609Network attack vector

Unauthenticated code execution via stack buffer overflow

Published Aug 4, 2021 · Updated Nov 7, 2024

Stack-based buffer overflow in Cisco RV340, RV340W, RV345, and RV345P firmware before 1.0.03.22 allows remote attackers to execute code. The web-based management interface improperly validates a crafted HTTP request, triggering the stack-based overflow. No authentication or user interaction is required; exploitation permits arbitrary code execution or a device reload, and WAN exposure requires remote management.

CVSS severity9.8
Critical
EPSS probability9.69%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in Cisco RV340, RV340W, RV345, and RV345P firmware before 1.0.03.22 allows remote attackers to execute code. The web-based management interface improperly validates a crafted HTTP request, triggering the stack-based overflow. No authentication or user interaction is required; exploitation permits arbitrary code execution or a device reload, and WAN exposure requires remote management.

The record

CVE
CVE-2021-1609
Published
Aug 4, 2021
Updated
Nov 7, 2024
Vendor
ClamAV
Product
Cisco Small Business RV Series Router Firmware
Classifications
CWE-121, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 4, 2021CVE publishedPublication date reported by the CVE source.
  2. Nov 7, 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

9.8Cisco Systems, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
10.0NIST NVDAV:N/AC:L/Au:N/C:C/I:C/A:C

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-121Stack-based Buffer Overflow
T1190Exploit Public-Facing Application

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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