CVE-2022-20703Known exploitation

Malicious firmware installation via improper image verification

Published Feb 10, 2022 · Updated Oct 21, 2025

Digital-signature bypass in Cisco Small Business RV router firmware allows local users to install and boot malicious software images. The image-verification feature improperly verifies software images during installation, accepting unsigned code for installation or execution. Local access without authentication is sufficient, and exploitation permits persistent malicious firmware or unsigned binaries to run on the router.

CVSS severity9.3
Critical
EPSS probability9.20%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Digital-signature bypass in Cisco Small Business RV router firmware allows local users to install and boot malicious software images. The image-verification feature improperly verifies software images during installation, accepting unsigned code for installation or execution. Local access without authentication is sufficient, and exploitation permits persistent malicious firmware or unsigned binaries to run on the router.

The record

CVE
CVE-2022-20703
Published
Feb 10, 2022
Updated
Oct 21, 2025
Vendor
ClamAV
Product
Cisco Small Business RV Series Router Firmware
Classifications
CWE-121, T1601.001
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 10, 2022CVE publishedPublication date reported by the CVE source.
  2. Mar 3, 2022Exploitation reportedCISA Known Exploited Vulnerabilities Catalog listing
  3. Oct 21, 2025Record 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 vectorlocal
Required privilegesunauthenticated

What is affected?

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

Published CVSS scores

9.3Cisco Systems, Inc.CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
8.0NIST NVDCVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
7.2NIST NVDAV:L/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationReported
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-121Stack-based Buffer Overflow
T1601.001Patch System Image

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.

Reported exploitation

Technologies

Your stack

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Your stack

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