#VU646 Resource exhaustion in OpenSSL - CVE-2016-6304

Vulnerability identifier: #VU646

Vulnerability risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2016-6304

CWE-ID: CWE-400

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
OpenSSL
Server applications / Encryption software

Vendor: OpenSSL Software Foundation

Description

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

The vulnerability exists due to improper resource management in OCSP stapling implementation in OpenSSL. A remote attacker can multiple requests with a large OCSP Status Request extension and consume all available memory on the system.

Mitigation
Install update from vendor's website.

Vulnerable software versions

OpenSSL: 1.0.1q - 1.0.1p, 1.0.2g - 1.0.2, 1.1.0

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External links
https://www.openssl.org/news/secadv/20160922.txt

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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.