CVE-2017-5447
CVE-2017-5447 is a critical-severity vulnerability in Mozilla Firefox with a CVSS 3.x base score of 9.1. Its EPSS exploit-prediction score of 18% places it in the 97th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-416.
Key facts
- Severity: Critical (CVSS 3.x base score 9.1)
- CVSS v2: 6.4
- EPSS exploit prediction: 18% (97th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-416
- Affected product: Mozilla Firefox
- Published:
- Last modified:
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.
Frequently asked questions
- What is CVE-2017-5447?
- 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.
- How severe is CVE-2017-5447?
- CVE-2017-5447 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability high.
- Is CVE-2017-5447 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 18% (97th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2017-5447?
- CVE-2017-5447 primarily affects Mozilla Firefox. In total, 17 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2017-5447?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
- When was CVE-2017-5447 published?
- CVE-2017-5447 was published on 2018-06-11 and last updated on 2026-06-17.
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/
Affected products (17)
- cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux:6.0:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_desktop:6.0:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_desktop:7.0:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_server:6.0:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_server_aus:7.3:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_server_aus:7.4:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_server_eus:7.3:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_server_eus:7.4:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_server_eus:7.5:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_workstation:6.0:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:*
- cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
- cpe:2.3:a:mozilla:firefox:52.0:*:*:*:*:*:*:*
- cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*
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