LibreSSL up to 2.6.4/2.7.3 DSA/ECDSA Key information disclosure

Summaryinfo

A vulnerability classified as problematic has been found in LibreSSL up to 2.6.4/2.7.3. This vulnerability affects unknown code of the component DSA/ECDSA Handler. The manipulation leads to information disclosure (Key). This vulnerability is listed as CVE-2018-12434. The attack must be carried out locally. There is no available exploit. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in LibreSSL up to 2.6.4/2.7.3. It has been rated as problematic. This issue affects some unknown processing of the component DSA/ECDSA Handler. The manipulation with an unknown input leads to a information disclosure vulnerability (Key). Using CWE to declare the problem leads to CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. Impacted is confidentiality. The summary by CVE is:

LibreSSL before 2.6.5 and 2.7.x before 2.7.4 allows a memory-cache side-channel attack on DSA and ECDSA signatures, aka the Return Of the Hidden Number Problem or ROHNP. To discover a key, the attacker needs access to either the local machine or a different virtual machine on the same physical host.

The bug was discovered 06/13/2018. The weakness was presented 06/15/2018 (Website). The advisory is shared at ftp.openbsd.org. The identification of this vulnerability is CVE-2018-12434 since 06/14/2018. An attack has to be approached locally. No form of authentication is needed for a successful exploitation. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1592 for this issue.

The vulnerability was handled as a non-public zero-day exploit for at least 1 days. During that time the estimated underground price was around $0-$5k. The vulnerability scanner Nessus provides a plugin with the ID 112264 (openSUSE Security Update : libressl (openSUSE-2018-950)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family SuSE Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 171549 (OpenSUSE Security Update for libressl (openSUSE-SU-2018:2597-1)).

Upgrading to version 2.6.5 or 2.7.4 eliminates this vulnerability. A possible mitigation has been published 3 months after the disclosure of the vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (112264). See VDB-114984 for similar entry. If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Name

• LibreSSL

Version

• 2.6.0
• 2.6.1
• 2.6.2
• 2.6.3
• 2.6.4
• 2.7.0
• 2.7.1
• 2.7.2
• 2.7.3

CPE 2.3info

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CPE 2.2info

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Entryinfo

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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