CVE-2022-20705Public exploitNetwork attack vector

Partial administrative access via weak session identifiers

Published Feb 10, 2022 · Updated Nov 6, 2024

Improper session management in Cisco Small Business RV router firmware allows remote attackers to gain partial administrative access. The web UI uses weak entropy for session identifiers, while its NGINX sessionid-cookie handling fails to validate a user-controlled path before file operations. No authentication or user interaction is required, and access enables unauthorized web UI actions with privileges up to the administrative user.

CVSS severity5.3
Medium
EPSS probability80.03%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper session management in Cisco Small Business RV router firmware allows remote attackers to gain partial administrative access. The web UI uses weak entropy for session identifiers, while its NGINX sessionid-cookie handling fails to validate a user-controlled path before file operations. No authentication or user interaction is required, and access enables unauthorized web UI actions with privileges up to the administrative user.

The record

CVE
CVE-2022-20705
Published
Feb 10, 2022
Updated
Nov 6, 2024
Vendor
ClamAV
Product
Cisco Small Business RV Series Router Firmware
Classifications
CWE-121, CWE-787, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 10, 2022CVE publishedPublication date reported by the CVE source.
  2. Nov 6, 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

5.3Cisco PSIRTCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
10.0Cisco Systems, Inc. CNA recordCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
7.5NIST National Vulnerability DatabaseAV:N/AC:L/Au:N/C:P/I:P/A:P
9.8NIST National Vulnerability DatabaseCVSS: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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-121Stack-based Buffer Overflow
CWE-787Out-of-bounds Write
T1190Exploit Public-Facing Application

Public exploit references

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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