What’s Vulnerable › Vulnerabilities

CVE-2023-5721

• Severity: medium (CVSS 4.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.9% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2023-10-25 · updated 2026-06-17
• Weakness: CWE-1021

Description

It was possible for certain browser prompts and dialogs to be activated or dismissed unintentionally by the user due to an insufficient activation-delay. This vulnerability affects Firefox < 119, Firefox ESR < 115.4, and Thunderbird < 115.4.1.

Affected products

• Debian Linux: 10.0, 11.0
• Mozilla Firefox: before 119.0 — fixed in 119.0
• Mozilla Firefox ESR: before 115.4 — fixed in 115.4
• Mozilla Thunderbird: before 115.4.1 — fixed in 115.4.1

How to fix

Upgrade to a fixed version: Mozilla Firefox 119.0; Mozilla Firefox ESR 115.4; Mozilla Thunderbird 115.4.1. Check the vendor advisory for mitigations.

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=1830820
• https://lists.debian.org/debian-lts-announce/2023/10/msg00037.html
• https://lists.debian.org/debian-lts-announce/2023/10/msg00042.html
• https://www.debian.org/security/2023/dsa-5535
• https://www.debian.org/security/2023/dsa-5538
• https://www.mozilla.org/security/advisories/mfsa2023-45/
• https://www.mozilla.org/security/advisories/mfsa2023-46/
• https://www.mozilla.org/security/advisories/mfsa2023-47/
• https://bugzilla.mozilla.org/show_bug.cgi?id=1830820
• https://lists.debian.org/debian-lts-announce/2023/10/msg00037.html
• https://lists.debian.org/debian-lts-announce/2023/10/msg00042.html
• https://www.debian.org/security/2023/dsa-5535

Get alerted when CVE-2023-5721 or the next vulnerability affects your stack