In Libgcrypt before 1.7.7, an attacker who learns the EdDSA session key (from side-channel observation during the signing process) can easily recover the long-term secret key. 1.7.7 makes a cipher/ecc-eddsa.c change to store this session key in secure memory, to ensure that constant-time point operations are used in the MPI library.

An update of the libgcrypt package has been released.

The remote Ubuntu 14.04 LTS / 16.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-3347-1 advisory.

    Daniel J. Bernstein, Joachim Breitner, Daniel Genkin, Leon Groot Bruinderink, Nadia Heninger, Tanja Lange,     Christine van Vredendaal, and Yuval Yarom discovered that Libgcrypt was susceptible to an attack via side     channels. A local attacker could use this attack to recover RSA private keys. (CVE-2017-7526)

    It was discovered that Libgcrypt was susceptible to an attack via side channels. A local attacker could     use this attack to possibly recover EdDSA private keys. This issue only applied to Ubuntu 16.04 LTS,     Ubuntu 16.10 and Ubuntu 17.04. (CVE-2017-9526)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

This update for libgcrypt fixes the following issues :

  - CVE-2017-9526: Store the session key in secure memory to     ensure that constant time point operations are used in     the MPI library. (bsc#1042326)

  - Don't require secure memory for the fips selftests, this     prevents the 'Oops, secure memory pool already     initialized' warning. (bsc#931932)

This update was imported from the SUSE:SLE-12:Update update project.

This update for libgcrypt fixes the following issues :

  - CVE-2017-9526: Store the session key in secure memory to     ensure that constant time point operations are used in     the MPI library. (bsc#1042326)

  - Don't require secure memory for the fips selftests, this     prevents the 'Oops, secure memory pool already     initialized' warning. (bsc#931932)

Note that Tenable Network Security has extracted the preceding description block directly from the SUSE security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

It was discovered that a side channel attack in the EdDSA session key handling in Libgcrypt may result in information disclosure.

ID	Name	Product	Family	Severity
121743	Photon OS 1.0: Libgcrypt PHSA-2017-0040	Nessus	PhotonOS Local Security Checks	medium
101231	Ubuntu 14.04 LTS / 16.04 LTS : Libgcrypt vulnerabilities (USN-3347-1)	Nessus	Ubuntu Local Security Checks	medium
101136	openSUSE Security Update : libgcrypt (openSUSE-2017-743)	Nessus	SuSE Local Security Checks	medium
100910	SUSE SLED12 / SLES12 Security Update : libgcrypt (SUSE-SU-2017:1608-1)	Nessus	SuSE Local Security Checks	medium
100774	Debian DSA-3880-1 : libgcrypt20 - security update	Nessus	Debian Local Security Checks	medium

Detections

Analytics

CVE-2017-9526

medium

Tenable Plugins

medium

medium

medium

medium

medium