#VU1962 Information disclosure


Published: 2016-12-21 | Updated: 2018-03-30

Vulnerability identifier: #VU1962

Vulnerability risk: Low

CVSSv3.1: 4.1 [CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2016-0702

CWE-ID: CWE-200

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
OpenSSL
Server applications / Encryption software

Vendor: OpenSSL Software Foundation

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".

Mitigation
Update to version 1.0.1s or 1.0.2g.

Vulnerable software versions

OpenSSL: 1.0.1, 1.0.1a, 1.0.1b, 1.0.1c, 1.0.1d, 1.0.1e, 1.0.1f, 1.0.1g, 1.0.1h, 1.0.1i, 1.0.1j, 1.0.1k, 1.0.1l, 1.0.1m, 1.0.1n, 1.0.1o, 1.0.1p, 1.0.1q, 1.0.1r, 1.0.2, 1.0.2a, 1.0.2b, 1.0.2c, 1.0.2d, 1.0.2e, 1.0.2f

CPE

External links
http://openssl.org/news/secadv/20160301.txt


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.


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