Vulnerability identifier: #VU1886

Vulnerability risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2016-2161

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Apache HTTP Server
Server applications / Web servers

Vendor: Apache Foundation

Description
The vulnerability allows a remote attacker to cause denial of service attack.

The vulnerability exists due to input validation error in mod_auth_digest module when parsing malicious HTTP requests. A remote attacker can send a specially crafted HTTP request to affected server and cause server crash.

Successful exploitation of the vulnerability will result in crash of each server instance.

Mitigation
Install the latest version Apache HTTP Server 2.4.25.

Vulnerable software versions

Apache HTTP Server: 2.2.0 - 2.4.23

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External links
http://httpd.apache.org/security/vulnerabilities_24.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.