CVE-2023-29540Public exploitNetwork attack vector

Sandbox bypass via redirected source map URL

Published Jun 2, 2023 · Updated Jan 9, 2025

Open redirect in Mozilla Firefox, Firefox for Android, and Firefox Focus for Android before 112 allows remote attackers to bypass iframe sandboxing. The DevTools source-map loader validates the initial sourceMappingURL protocol but follows a redirect to an external protocol without rechecking the destination. Triggering the external-protocol prompt requires attacker-controlled content and opening Developer Tools; Mozilla reproduced the behavior only on Windows 10.

CVSS severity6.1
Medium
EPSS probability0.32%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Open redirect in Mozilla Firefox, Firefox for Android, and Firefox Focus for Android before 112 allows remote attackers to bypass iframe sandboxing. The DevTools source-map loader validates the initial sourceMappingURL protocol but follows a redirect to an external protocol without rechecking the destination. Triggering the external-protocol prompt requires attacker-controlled content and opening Developer Tools; Mozilla reproduced the behavior only on Windows 10.

The record

CVE
CVE-2023-29540
Published
Jun 2, 2023
Updated
Jan 9, 2025
Vendor
Mozilla
Product
Firefox
Classifications
CWE-601
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 2, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 9, 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=unspecified <112

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mozilla · Firefoxversion=unspecified <112
Mozilla · Firefox for Androidversion=unspecified <112
Mozilla · Firefox Focus for Androidversion=unspecified <112

Published CVSS scores

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 exploitPublished

Weakness, pattern, technique

CWE-601URL Redirection to Untrusted Site ('Open Redirect')

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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