What’s Vulnerable › Vulnerabilities

CVE-2024-9394

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2024-10-01 · updated 2026-06-17
• Weakness: CWE-79

Description

An attacker could, via a specially crafted multipart response, execute arbitrary JavaScript under the `resource://devtools` origin. This could allow them to access cross-origin JSON content. This access is limited to "same site" documents by the Site Isolation feature on desktop clients, but full cross-origin access is possible on Android versions. This vulnerability affects Firefox < 131, Firefox ESR < 128.3, Firefox ESR < 115.16, Thunderbird < 128.3, and Thunderbird < 131.

Affected products

• Mozilla Firefox: before 131.0 — fixed in 131.0
• Mozilla Firefox ESR: before 115.16.0; from 116.0 before 128.3.0 — fixed in 115.16.0, 128.3.0
• Mozilla Thunderbird: before 128.3; 129.0-beta, 129.0-beta2, 129.0-beta3, 129.0-beta4, 129.0-beta5, 129.0-beta6 — fixed in 128.3

How to fix

Upgrade to a fixed version: Mozilla Firefox 131.0; Mozilla Firefox ESR 115.16.0, 128.3.0; Mozilla Thunderbird 128.3. Check the vendor advisory for mitigations.

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=1918874
• https://www.mozilla.org/security/advisories/mfsa2024-46/
• https://www.mozilla.org/security/advisories/mfsa2024-47/
• https://www.mozilla.org/security/advisories/mfsa2024-48/
• https://www.mozilla.org/security/advisories/mfsa2024-49/
• https://www.mozilla.org/security/advisories/mfsa2024-50/
• https://lists.debian.org/debian-lts-announce/2024/10/msg00004.html
• https://lists.debian.org/debian-lts-announce/2024/10/msg00006.html

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