#VU99779 Improper input validation in Linux kernel - CVE-2006-5173

Vulnerability identifier: #VU99779

Vulnerability risk: Low

CVSSv4.0: 1.1 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2006-5173

CWE-ID: CWE-20

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Linux kernel
Operating systems & Components / Operating system

Vendor: Linux Foundation

Description

The vulnerability allows a local user to perform service disruption.

Linux kernel does not properly save or restore EFLAGS during a context switch, or reset the flags when creating new threads, which allows local users to cause a denial of service (process crash), as demonstrated using a process that sets the Alignment Check flag (EFLAGS 0x40000), which triggers a SIGBUS in other processes that have an unaligned access.

Mitigation
Install update from vendor's repository.

Vulnerable software versions

Linux kernel: All versions

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External links
https://kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=47a5c6fa0e204a2b63309c648bb2fde36836c826
https://secunia.com/advisories/23361
https://secunia.com/advisories/23384
https://secunia.com/advisories/23474
https://secunia.com/advisories/23593
https://secunia.com/advisories/25691
https://www.mandriva.com/security/advisories?name=MDKSA-2007:002
https://www.novell.com/linux/security/advisories/2006_79_kernel.html
https://www.securityfocus.com/archive/1/471457
https://www.securityfocus.com/bid/21851
https://www.ubuntu.com/usn/usn-395-1

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Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.