Vulnerability identifier: #VU20198

Vulnerability risk: Medium

CVSSv3.1: 5.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-9516

CWE-ID: CWE-400

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
nginx
Server applications / Web servers

Vendor: NGINX

Description

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

The vulnerability exists due to improper input validation when processing HTTP/2 requests within the ngx_http_v2_module module. A remote attacker can send a specially crafted HTTP/2 request the affected server, consume all available CPU resources and perform a denial of service (DoS) attack.

Successful exploitation of the vulnerability requires that support for HTTP/2 is enabled.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

nginx: 1.17.0 - 1.17.2, 1.16.0, 1.15.0 - 1.15.12, 1.14.0 - 1.14.2, 1.13.0 - 1.13.12, 1.12.0 - 1.12.2, 1.11.0 - 1.11.13, 1.10.0 - 1.10.3, 1.9.5 - 1.9.15

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External links
http://mailman.nginx.org/pipermail/nginx-announce/2019/000249.html

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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.