LibreSSL 2.7.0/2.7.1 x509_vpm.c int_x509_param_set_hosts certificate validation

Summaryinfo

A vulnerability, which was classified as critical, was found in LibreSSL 2.7.0/2.7.1. Affected by this issue is the function int_x509_param_set_hosts in the library lib/libcrypto/x509/x509_vpm.c. The manipulation results in certificate validation. This vulnerability is cataloged as CVE-2018-8970. The attack may be launched remotely. There is no exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability classified as critical has been found in LibreSSL 2.7.0/2.7.1. Affected is the function int_x509_param_set_hosts in the library lib/libcrypto/x509/x509_vpm.c. The manipulation with an unknown input leads to a certificate validation vulnerability. CWE is classifying the issue as CWE-295. The product does not validate, or incorrectly validates, a certificate. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

The int_x509_param_set_hosts function in lib/libcrypto/x509/x509_vpm.c in LibreSSL 2.7.0 before 2.7.1 does not support a certain special case of a zero name length, which causes silent omission of hostname verification, and consequently allows man-in-the-middle attackers to spoof servers and obtain sensitive information via a crafted certificate. NOTE: the LibreSSL documentation indicates that this special case is supported, but the BoringSSL documentation does not.

The bug was discovered 03/22/2018. The weakness was shared 03/24/2018 (Website). The advisory is shared for download at boringssl.googlesource.com. This vulnerability is traded as CVE-2018-8970 since 03/24/2018. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1587.003.

The vulnerability was handled as a non-public zero-day exploit for at least 2 days. During that time the estimated underground price was around $0-$5k. The vulnerability scanner Nessus provides a plugin with the ID 112267 (openSUSE Security Update : libressl (openSUSE-2018-953)), 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 eliminates this vulnerability. A possible mitigation has been published 6 months after the disclosure of the vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (112267). The entry VDB-119573 is related to this item. VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

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• LibreSSL

Version

• 2.7.0
• 2.7.1

License

• open-source

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VulDB is the best source for vulnerability data and more expert information about this specific topic.

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