CVE-2015-5296: Canonical Ubuntu Linux

Medium severity, CVSS 5.4. EPSS: 7.3% chance of exploitation in the next 30 days.

Samba 3.x and 4.x before 4.1.22, 4.2.x before 4.2.7, and 4.3.x before 4.3.3 supports connections that are encrypted but unsigned, which allows man-in-the-middle attackers to conduct encrypted-to-unencrypted downgrade attacks by modifying the client-server data stream, related to clidfs.c, libsmb_server.c, and smbXcli_base.c.

Affected products

• Canonical Ubuntu Linux: version 12.04 only; version 14.04 only; version 15.04 only; version 15.10 only
• Debian Debian Linux: version 7.0 only; version 8.0 only
• Samba Samba: from 3.2.0, before 4.1.22 (fixed in 4.1.22); from 4.2.0, before 4.2.7 (fixed in 4.2.7); from 4.3.0, before 4.3.3 (fixed in 4.3.3)

Published 2015-12-29. Last modified 2026-06-17.