#VU30638 Integer overflow in Linux kernel - CVE-2019-18805

Vulnerability identifier: #VU30638

Vulnerability risk: High

CVSSv4.0: 8.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2019-18805

CWE-ID: CWE-190

Exploitation vector: Network

Exploit availability: No

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

Vendor: Linux Foundation

Description

The vulnerability allows a remote non-authenticated attacker to execute arbitrary code.

An issue was discovered in net/ipv4/sysctl_net_ipv4.c in the Linux kernel before 5.0.11. There is a net/ipv4/tcp_input.c signed integer overflow in tcp_ack_update_rtt() when userspace writes a very large integer to /proc/sys/net/ipv4/tcp_min_rtt_wlen, leading to a denial of service or possibly unspecified other impact, aka CID-19fad20d15a6.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Linux kernel: 5.0.0 - 5.0.10

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External links
https://lists.opensuse.org/opensuse-security-announce/2019-11/msg00035.html
https://lists.opensuse.org/opensuse-security-announce/2019-11/msg00039.html
https://access.redhat.com/errata/RHSA-2020:0740
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.0.11
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=19fad20d15a6494f47f85d869f00b11343ee5c78
https://security.netapp.com/advisory/ntap-20191205-0001/

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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.