TLS Padding Oracle in MatrixSSL

1) TLS Padding Oracle

EUVDB-ID: #VU84951

Risk: Medium

CVSSv3.1: 5.3 [CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2016-6883

CWE-ID: CWE-310 - Cryptographic Issues

Exploit availability: No

Description

The vulnerability allows a remote attacker to decrypt TLS traffic.

The vulnerability exists due to an error in TLS implementation. A remote attacker with ability to establish a large number of TLS connections with the target server can conduct an adaptive-chosen ciphertext attack against RSA cipher and gain access to sensitive information.

The attack is known as "ROBOT" (Return Of Bleichenbacher's Oracle Threat).

Mitigation

Install update from vendor's website.

Vulnerable software versions

MatrixSSL: before 3.8.3

External links

http://www.openwall.com/lists/oss-security/2016/08/19/8
http://github.com/matrixssl/matrixssl/blob/master/CHANGES.md

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the local network (LAN).

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.