Information disclosure in OpenBSD LibreSSL



Published: 2018-08-16
Risk Low
Patch available YES
Number of vulnerabilities 1
CVE-ID CVE-2018-12434
CWE-ID CWE-200
Exploitation vector Local
Public exploit N/A
Vulnerable software
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LibreSSL
Universal components / Libraries / Libraries used by multiple products

Vendor OpenBSD

Security Bulletin

This security bulletin contains one low risk vulnerability.

1) Memory-cache side-channel timing attack

EUVDB-ID: #VU14438

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-2018-12434

CWE-ID: CWE-200 - Information exposure

Exploit availability: No

Description

The vulnerability allows a local attacker to obtain potentially sensitive information.

The vulnerability exists due to information leak via memory caches when modular addition calculations may not run in constant time when private keys are used to generate Elliptic Curve Digital Signature Algorithm (ECDSA) or Digital Signature Algorithm (DSA) signatures. A local attacker can conduct memory-cache side-channel timing attacks and recover sensitive information, such as the ECDSA or DSA private keys used to generate the signatures, which could be used to conduct additional attacks.

Mitigation

Update to version 2.6.5, 2.7.4.

Vulnerable software versions

LibreSSL: 2.6.0 - 2.7.3

External links

http://ftp.openbsd.org/pub/OpenBSD/LibreSSL/libressl-2.6.5-relnotes.txt
http://ftp.openbsd.org/pub/OpenBSD/LibreSSL/libressl-2.7.4-relnotes.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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