CVE-2021-29979Network attack vector

Cross-site scripting via shared active content

Published Aug 2, 2021 · Updated Aug 3, 2024

Cross-site scripting in Mozilla Hubs Cloud before mozillareality/reticulum/1.0.1/20210618012634 allows remote attackers to run JavaScript. Reticulum serves downloadable shared HTML and JavaScript with an implicit content type that permits script execution in the instance's primary hosting domain. A recipient must download the shared active content; successful execution can read or alter same-origin data available to that browsing session.

CVSS severity6.1
Medium
EPSS probability0.67%
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 Mozilla Hubs Cloud before mozillareality/reticulum/1.0.1/20210618012634 allows remote attackers to run JavaScript. Reticulum serves downloadable shared HTML and JavaScript with an implicit content type that permits script execution in the instance's primary hosting domain. A recipient must download the shared active content; successful execution can read or alter same-origin data available to that browsing session.

The record

CVE
CVE-2021-29979
Published
Aug 2, 2021
Updated
Aug 3, 2024
Vendor
Mozilla
Product
Hubs Cloud
Classifications
CWE-79, T1204.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 2, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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 <mozillareality/reticulum/1.0.1/20210618012634

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mozilla · Hubs Cloudversion=unspecified <mozillareality/reticulum/1.0.1/20210618012634

Published CVSS scores

4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:P/A:N
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')
T1204.002Malicious File

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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