Vulnerability identifier: #VU65650

Vulnerability risk: Medium

CVSSv3.1: 5.2 [CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2016-2402

CWE-ID: CWE-300

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
OkHttp
Mobile applications / Libraries for mobile applications

Vendor: Square

Description

The vulnerability allows a remote attacker to perform MitM attack.

The vulnerability exists due to an unspecified error. A remote attacker can send a certificate chain with a certificate from a non-pinned trusted CA and the pinned certificate to bypass certificate pinning.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

OkHttp: 2.7.0 - 2.7.3, 3.1.0 - 3.1.1

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External links
http://www.openwall.com/lists/oss-security/2016/02/10/8
http://www.openwall.com/lists/oss-security/2016/02/18/7
http://koz.io/pinning-cve-2016-2402/
http://lists.apache.org/thread.html/rd0e44e8ef71eeaaa3cf3d1b8b41eb25894372e2995ec908ce7624d26@%3Ccommits.pulsar.apache.org%3E
http://publicobject.com/2016/02/11/okhttp-certificate-pinning-vulnerability/

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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.