What’s Vulnerable › Vulnerabilities

CVE-2017-5447

• Severity: critical (CVSS 9.1 v3.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 17.0% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2018-06-11 · updated 2026-06-17
• Weakness: CWE-416

Description

An out-of-bounds read during the processing of glyph widths during text layout. This results in a potentially exploitable crash and could allow an attacker to read otherwise inaccessible memory. This vulnerability affects Thunderbird < 52.1, Firefox ESR < 45.9, Firefox ESR < 52.1, and Firefox < 53.

Affected products

• Debian Linux: 9.0
• Mozilla Firefox: before 45.9.0; before 53.0; 52.0 — fixed in 45.9.0, 53.0
• Mozilla Thunderbird: before 52.1.0 — fixed in 52.1.0
• Red Hat Enterprise Linux: 6.0, 7.0
• RedHat Enterprise Linux Desktop: 6.0, 7.0
• RedHat Enterprise Linux Server: 6.0, 7.0
• RedHat Enterprise Linux Server Aus: 7.3, 7.4
• RedHat Enterprise Linux Server Eus: 7.3, 7.4, 7.5
• RedHat Enterprise Linux Workstation: 6.0, 7.0

How to fix

Upgrade to a fixed version: Mozilla Firefox 45.9.0, 53.0; Mozilla Thunderbird 52.1.0. Check the vendor advisory for mitigations.

References

• http://www.securityfocus.com/bid/97940
• http://www.securitytracker.com/id/1038320
• https://access.redhat.com/errata/RHSA-2017:1104
• https://access.redhat.com/errata/RHSA-2017:1106
• https://access.redhat.com/errata/RHSA-2017:1201
• https://bugzilla.mozilla.org/show_bug.cgi?id=1343552
• https://www.debian.org/security/2017/dsa-3831
• https://www.exploit-db.com/exploits/42071/
• https://www.mozilla.org/security/advisories/mfsa2017-10/
• https://www.mozilla.org/security/advisories/mfsa2017-11/
• https://www.mozilla.org/security/advisories/mfsa2017-12/
• https://www.mozilla.org/security/advisories/mfsa2017-13/

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