#VU12112 NULL pointer dereference in Linux kernel - CVE-2018-1095

Vulnerability identifier: #VU12112

Vulnerability risk: Medium

CVSSv4.0: 4.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2018-1095

CWE-ID: CWE-476

Exploitation vector: Network

Exploit availability: No

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

Vendor: Linux Foundation

Description
The vulnerability allows a remote authenticated attacker to cause DoS condition on the target system.

The weakness exists in the ext4_xattr_check_entries function in fs/ext4/xattr.c due to improper validation of xattr sizes, which causes misinterpretation of a size as an error code. A remote attacker can submit a specially crafted ext4 image, trigger NULL pointer dereference and cause the service to crash.

Mitigation
Update to version 4.15.16.

Vulnerable software versions

Linux kernel: 4.15.0 - 4.15.15

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External links
https://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git/commit/?id=ce3fd194fcc6fbdc00ce095a85...

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

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