Information disclosure in OpenSSL - CVE-2016-0702

 

Information disclosure in OpenSSL - CVE-2016-0702

Published: December 21, 2016 / Updated: March 30, 2018


Vulnerability identifier: #VU1962
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2016-0702
CWE-ID: CWE-200
Exploitation vector: Local access
Exploit availability: No public exploit available
Vendor: OpenSSL Software Foundation
Affected software:
OpenSSL

Detailed vulnerability description

The vulnerability allows a local attacker to decrypt data passed via encrypted SSL connection.

The vulnerability exists in the MOD_EXP_CTIME_COPY_FROM_PREBUF() function in crypto/bn/bn_exp.c. The application does not properly consider cache-bank access times during modular exponentiation, which makes it easier for local users to discover RSA keys by running a crafted application on the same Intel Sandy Bridge CPU core as a victim and leveraging cache-bank conflicts.

The vulnerability was dubbed "CacheBleed".

How to mitigate CVE-2016-0702

Update to version 1.0.1s or 1.0.2g.

Sources