Vulnerability identifier: #VU1010

Vulnerability risk: Low

CVSSv3.1: 4.8 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2015-8952

CWE-ID: CWE-264

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 cause DoS conditions on the target system.

The weakness exists due to mbcache feature in the ext2 and ext4 filesystem implementations. Improper handling of xattr block caching lets attackers to trigger soft lockup via filesystem operations in environments that use many attributes.

Successful exploitation of the vulnerability may result in denial of service on the vulnerable system.

Mitigation
Update to version 4.6.

Vulnerable software versions

Linux kernel: 4.4.1 - 4.4.25, 4.5.1 - 4.5.7, 4.3.1 - 4.3.6, 4.2.1 - 4.2.8, 4.0.1 - 4.0.9, 4.6.2 - 4.6.4-1 , 3.16.7-ckt25-2 - 3.16.7-ckt25-2+deb8u3 , 3.2.78-1 - 3.2.81-1, 4.1.1 - 4.1.36

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External links
http://bugzilla.redhat.com/show_bug.cgi?id=1360968
http://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.1.37

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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.