#VU95748 Improper input validation in Linux kernel - CVE-2007-3731

Vulnerability identifier: #VU95748

Vulnerability risk: Low

CVSSv4.0: 4.3 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2007-3731

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 a denial of service (DoS) attack.

The Linux kernel 2.6.20 and 2.6.21 does not properly handle an invalid LDT segment selector in %cs (the xcs field) during ptrace single-step operations, which allows local users to cause a denial of service (NULL dereference and OOPS) via certain code that makes ptrace PTRACE_SETREGS and PTRACE_SINGLESTEP requests, related to the TRACE_IRQS_ON function, and possibly related to the arch_ptrace function.

Mitigation
Install update from vendor's repository.

Vulnerable software versions

Linux kernel: All versions

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External links
https://bugzilla.kernel.org/show_bug.cgi?id=8765
https://bugzilla.redhat.com/show_bug.cgi?id=248324
https://www.debian.org/security/2007/dsa-1378
https://www.redhat.com/support/errata/RHSA-2007-0940.html
https://www.ubuntu.com/usn/usn-518-1
https://www.securityfocus.com/bid/25801
https://secunia.com/advisories/26935
https://secunia.com/advisories/26955
https://secunia.com/advisories/26978
https://secunia.com/advisories/27322
https://wiki.rpath.com/wiki/Advisories:rPSA-2008-0094
https://issues.rpath.com/browse/RPL-2304
https://secunia.com/advisories/29159
https://osvdb.org/37286
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A10394
https://www.securityfocus.com/archive/1/488972/100/0/threaded
https://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commitdiff%3Bh=29eb51101c02df517ca64ec472d7501127ad1da8
https://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commitdiff%3Bh=a10d9a71bafd3a283da240d2868e71346d2aef6f

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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.