#VU7410 Integer overflow in nginx - CVE-2017-7529

Vulnerability identifier: #VU7410

Vulnerability risk: Medium

CVSSv4.0: 7.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/U:Green]

CVE-ID: CVE-2017-7529

CWE-ID: CWE-190

Exploitation vector: Network

Exploit availability: Yes

Vulnerable software:
nginx
Server applications / Web servers

Vendor: NGINX

Description
The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to integer overflow when processing specially crafted requests. A remote attacker can send a malicious request to vulnerable server and gain access to potentially sensitive information.
 
When using nginx with standard modules this allows an attacker to obtain a cache file header if a response was returned from cache. In some configurations a cache file header may contain IP address of the backend server or other sensitive information.

Mitigation
Update to version 1.13.3 or 1.12.1.

Vulnerable software versions

nginx: 0.5.6 - 0.5.38, 0.6.0 - 0.6.1516, 0.7.0 - 0.7.69, 0.8.0 - 0.8.55, 1.2.0 - 1.2.9, 1.4.0 - 1.4.7, 1.6.0 - 1.6.3, 1.8.0 - 1.8.1, 1.10.0 - 1.13.2

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External links
https://nginx.org/en/CHANGES
https://mailman.nginx.org/pipermail/nginx-announce/2017/000200.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. However, proof of concept for this vulnerability is available.