What’s Vulnerable › Vulnerabilities

CVE-2009-4895

• Severity: medium (CVSS 4.7 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2010-09-08 · updated 2026-06-16
• Weakness: CWE-362

Description

Race condition in the tty_fasync function in drivers/char/tty_io.c in the Linux kernel before 2.6.32.6 allows local users to cause a denial of service (NULL pointer dereference and system crash) or possibly have unspecified other impact via unknown vectors, related to the put_tty_queue and __f_setown functions. NOTE: the vulnerability was addressed in a different way in 2.6.32.9.

Affected products

• Canonical Ubuntu Linux: 6.06, 8.04, 9.04, 9.10, 10.04, 10.10
• Debian Linux: 5.0
• Linux kernel: before 2.6.32.6 — fixed in 2.6.32.6

How to fix

Upgrade to a fixed version: Linux kernel 2.6.32.6. Check the vendor advisory for mitigations.

References

• http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=703625118069f9f8960d356676662d3db5a9d116
• http://www.debian.org/security/2010/dsa-2094
• http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.32.6
• http://www.openwall.com/lists/oss-security/2010/06/15/2
• http://www.openwall.com/lists/oss-security/2010/06/15/3
• http://www.openwall.com/lists/oss-security/2010/06/15/4
• http://www.openwall.com/lists/oss-security/2010/06/15/5
• http://www.ubuntu.com/usn/USN-1000-1
• https://bugzilla.kernel.org/show_bug.cgi?id=14605
• https://bugzilla.redhat.com/show_bug.cgi?id=559100
• http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=703625118069f9f8960d356676662d3db5a9d116
• http://www.debian.org/security/2010/dsa-2094

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