#VU357 Man-in-the-middle attack in Linux kernel - CVE-2016-5696

Vulnerability identifier: #VU357

Vulnerability risk: Low

CVSSv4.0: 5.5 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/U:Clear]

CVE-ID: CVE-2016-5696

CWE-ID: CWE-300

Exploitation vector: Network

Exploit availability: Yes

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

Vendor: Linux Foundation

Description

The vulnerability allows a remote attacker to write arbitrary files and cause DoS condition on the target system.

The weakness exists due to an error in net/ipv4/tcp_input.c while determining the rate of challenge ACK segments. A remote attacker can perform man-in-the-middle attack and hijack TCP sessions via a blind in-window attack.

Mitigation
Update to version 4.7.

Vulnerable software versions

Linux kernel: 4.6

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External links
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=75ff39ccc1bd5d3c455b68...

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

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.