Red Hat Enterprise Linux 7 update for openssl

1) Information disclosure

EUVDB-ID: #VU4133

Risk: Low

CVSSv3.1: 4.8 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2016-7056

CWE-ID: CWE-310 - Cryptographic Issues

Exploit availability: No

Description

The vulnerability allows a local user obtain potentially sensitive information.

The vulnerability exists due the OpenSSL does not properly set the BN_FLG_CONSTTIME for nonces when signing with the P-256 elliptic curve in ecdsa_sign_setup() function in crypto/ec/ecdsa_ossl.c. A local attacker can conduct a cache-timing attack and recover ECDSA P-256 private keys

Successful exploitation of this vulnerability may allow an attacker to obtain potentially sensitive information.

The vulnerability is discovered in OpenSSL 1.0.1u. Other versions may also be affected.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Red Hat Enterprise Linux EUS Compute Node: 7.4 - 7.7

Red Hat Enterprise Linux Server - Extended Update Support: 7.4 - 7.7

Red Hat Enterprise Linux Server - TUS: 7.6 - 7.7

Red Hat Enterprise Linux for Power, little endian - Extended Update Support: 7.4 - 7.7

Red Hat Enterprise Linux for Power, big endian - Extended Update Support: 7.4 - 7.7

Red Hat Enterprise Linux for IBM z Systems - Extended Update Support: 7.4 - 7.7

Red Hat Enterprise Linux Server - AUS: 7.4 - 7.7

Red Hat Enterprise Linux for Power, little endian: 7

Red Hat Enterprise Linux for Power, big endian: 7

Red Hat Enterprise Linux for IBM z Systems: 7

Red Hat Enterprise Linux for Scientific Computing: 7

Red Hat Enterprise Linux Desktop: 7

Red Hat Enterprise Linux Workstation: 7

Red Hat Enterprise Linux Server: 7

openssl (Red Hat package): before 1.0.2k-8.el7

External links

http://access.redhat.com/errata/RHBA-2017:1929

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

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