CVE-2023-49296Network attack vector

Browser-side code execution via unescaped error template

Published Dec 13, 2023 · Updated Aug 2, 2024

Reflected XSS in Arduino Cloud Agent before 1.3.6 allows remote attackers to execute browser-side code through a malicious link. The /certificate.crt handler passes attacker-controlled custom error text through Go's text/template package without contextual HTML escaping. Exploitation requires a victim to open the link, after which code runs in the browser context associated with the agent interface.

CVSS severity6.3
Medium
EPSS probability0.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reflected XSS in Arduino Cloud Agent before 1.3.6 allows remote attackers to execute browser-side code through a malicious link. The /certificate.crt handler passes attacker-controlled custom error text through Go's text/template package without contextual HTML escaping. Exploitation requires a victim to open the link, after which code runs in the browser context associated with the agent interface.

The record

CVE
CVE-2023-49296
Published
Dec 13, 2023
Updated
Aug 2, 2024
Vendor
Arduino
Product
Arduino Cloud Agent
Classifications
CWE-79, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 13, 2023CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 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=< 1.3.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Arduino · Arduino Cloud Agentversion=< 1.3.6

Published CVSS scores

6.3GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L
6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/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 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-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1203Exploitation for Client Execution

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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