#VU20198 Resource exhaustion in nginx - CVE-2019-9516

Vulnerability identifier: #VU20198

Vulnerability risk: Medium

CVSSv4.0: 4.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

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: 1.9.5 - 1.9.15, 1.10.0 - 1.17.2

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External links
https://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.