Vulnerability identifier: #VU9601

Vulnerability risk: Low

CVSSv3.1: 5.9 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2017-16939

CWE-ID: CWE-416

Exploitation vector: Local

Exploit availability: Yes

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

Vendor: Linux Foundation

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

The weakness exists in the XFRM dump policy implementation in net/xfrm/xfrm_user.c in the Linux kernel due to use-after-free error. A local attacker can make a specially crafted SO_RCVBUF setsockopt system call in conjunction with XFRM_MSG_GETPOLICY Netlink messages, trigger memory corruption and cause the service to crash.

Successful exploitation of the vulnerability results in denial of service.

Mitigation
Update to version 4.13.11.

Vulnerable software versions

Linux kernel: 4.13 - 4.13.10, 4.12 - 4.12.14, 4.11 - 4.11.12, 4.4.11, 4.10.0 - 4.10.17

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External links
http://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1137b5e2529a8f5ca8ee70...

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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. However, proof of concept for this vulnerability is available.