What’s Vulnerable › Vulnerabilities

CVE-2017-7843

• Severity: high (CVSS 7.5 v3.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 2.9% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2018-06-11 · updated 2026-06-17
• Weakness: CWE-200

Description

When Private Browsing mode is used, it is possible for a web worker to write persistent data to IndexedDB and fingerprint a user uniquely. IndexedDB should not be available in Private Browsing mode and this stored data will persist across multiple private browsing mode sessions because it is not cleared when exiting. This vulnerability affects Firefox ESR < 52.5.2 and Firefox < 57.0.1.

Affected products

• Debian Linux: 7.0, 8.0, 9.0
• Mozilla Firefox: before 57.0.1; before 52.5.2 — fixed in 52.5.2, 57.0.1
• RedHat Enterprise Linux Desktop: 6.0, 7.0
• RedHat Enterprise Linux Server: 6.0, 7.0
• RedHat Enterprise Linux Server Aus: 7.4
• RedHat Enterprise Linux Server Eus: 7.4, 7.5
• RedHat Enterprise Linux Workstation: 6.0, 7.0

How to fix

Upgrade to a fixed version: Mozilla Firefox 52.5.2, 57.0.1. Check the vendor advisory for mitigations.

References

• http://www.securityfocus.com/bid/102039
• http://www.securityfocus.com/bid/102112
• http://www.securitytracker.com/id/1039954
• https://access.redhat.com/errata/RHSA-2017:3382
• https://bugzilla.mozilla.org/show_bug.cgi?id=1410106
• https://lists.debian.org/debian-lts-announce/2017/12/msg00003.html
• https://www.debian.org/security/2017/dsa-4062
• https://www.mozilla.org/security/advisories/mfsa2017-27/
• https://www.mozilla.org/security/advisories/mfsa2017-28/
• http://www.securityfocus.com/bid/102039
• http://www.securityfocus.com/bid/102112
• http://www.securitytracker.com/id/1039954

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