CVE-2017-5383: Debian Linux

Medium severity, CVSS 5.3. EPSS: 2.5% chance of exploitation in the next 30 days.

URLs containing certain unicode glyphs for alternative hyphens and quotes do not properly trigger punycode display, allowing for domain name spoofing attacks in the location bar. This vulnerability affects Thunderbird < 45.7, Firefox ESR < 45.7, and Firefox < 51.

Affected products

• Debian Debian Linux: version 8.0 only
• Mozilla Firefox: before 51.0 (fixed in 51.0); before 45.7.0 (fixed in 45.7.0)
• Mozilla Thunderbird: before 45.7.0 (fixed in 45.7.0)
• Red Hat Enterprise Linux: version 5.0 only; version 6.0 only; version 7.0 only
• Red Hat Enterprise Linux Desktop: version 5.0 only; version 6.0 only; version 7.0 only
• Red Hat Enterprise Linux Server: version 5.0 only; version 6.0 only; version 7.0 only
• Red Hat Enterprise Linux Server Aus: version 7.3 only; version 7.4 only
• Red Hat Enterprise Linux Server Eus: version 7.3 only; version 7.4 only; version 7.5 only
• Red Hat Enterprise Linux Workstation: version 5.0 only; version 6.0 only; version 7.0 only

Published 2018-06-11. Last modified 2026-06-17.