CVE-2009-1633: Canonical Ubuntu Linux

High severity, CVSS 7.1. EPSS: 3% chance of exploitation in the next 30 days.

Multiple buffer overflows in the cifs subsystem in the Linux kernel before 2.6.29.4 allow remote CIFS servers to cause a denial of service (memory corruption) and possibly have unspecified other impact via (1) a malformed Unicode string, related to Unicode string area alignment in fs/cifs/sess.c; or (2) long Unicode characters, related to fs/cifs/cifssmb.c and the cifs_readdir function in fs/cifs/readdir.c.

Affected products

• Canonical Ubuntu Linux: version 6.06 only; version 8.04 only; version 8.10 only; version 9.04 only
• Debian Debian Linux: version 4.0 only; version 5.0 only
• Linux Linux Kernel: before 2.6.29.4 (fixed in 2.6.29.4)

Published 2009-05-28. Last modified 2026-06-16.