CVE-2020-3121Network attack vector

Script execution via insufficient web input validation

Published Jan 26, 2020 · Updated Nov 15, 2024

Cross-site scripting in Cisco 550X Series firmware 2.5.0.90 and earlier allows remote attackers to execute script via a malicious link. The web-based management interface fails to validate user-supplied input on a specific page before returning it to the browser. Exploitation requires a management-interface user to follow the crafted link, after which script runs in that interface's browser context and can access sensitive browser-based information.

CVSS severity6.1
Medium
EPSS probability1.07%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in Cisco 550X Series firmware 2.5.0.90 and earlier allows remote attackers to execute script via a malicious link. The web-based management interface fails to validate user-supplied input on a specific page before returning it to the browser. Exploitation requires a management-interface user to follow the crafted link, after which script runs in that interface's browser context and can access sensitive browser-based information.

The record

CVE
CVE-2020-3121
Published
Jan 26, 2020
Updated
Nov 15, 2024
Vendor
ClamAV
Product
Cisco 550X Series Stackable Managed Switches
Classifications
CWE-79, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 26, 2020CVE publishedPublication date reported by the CVE source.
  2. Nov 15, 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=unspecified <n/a

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ClamAV · Cisco 550X Series Stackable Managed Switchesversion=unspecified <n/a

Published CVSS scores

6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
6.1CiscoCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N/E:X/RL:X/RC:X
4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:P/A:N

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1189Drive-by Compromise

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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