#VU18947 Resource exhaustion in Linux kernel - CVE-2019-11479

Vulnerability identifier: #VU18947

Vulnerability risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2019-11479

CWE-ID: CWE-400

Exploitation vector: Network

Exploit availability: No

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

Vendor: Linux Foundation

Description

The vulnerability allows a remote attacker to perform denial of service (DoS) attack.

The vulnerability exists due to presence of hard-coded MSS value (48 bytes) in the Linux kernel source code. A remote attacker can fragment TCP resend queues significantly more than if a larger MSS were enforced and perform denial of service (DoS) attack.

Mitigation

Update your kernel to the latest version.

Vulnerable software versions

Linux kernel: 4.4.0 - 4.4.181, 4.9 - 4.9.181, 4.14 - 4.19.51, 5.0 - 5.0.21, 5.1 rc1 - 5.1.21

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External links
https://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.4.182
https://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.9.182
https://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.14.127
https://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.19.52
https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.1.11
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.2
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.2

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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.