The RSA and DSA decryption code in Nettle makes it easier for attackers to discover private keys via a cache side channel attack.

An update of the nettle package has been released.

The remote host is affected by the vulnerability described in GLSA-201706-21 (nettle: Information disclosure)

    It was found that nettle&rsquo;s RSA and DSA decryption code was vulnerable       to cache-related side channel attacks.
    See the referenced technical paper &ldquo;Cache Attacks Enable Bulk Key       Recovery on the Cloud&rdquo; below for details.
  Impact :

    An attacker could recover the private key from a co-located       virtual-machine instance.
  Workaround :

    There is no known workaround at this time.

This update for libnettle fixes the following issues :

  - CVE-2016-6489 :

  - Reject invalid RSA keys with even modulo.

  - Check for invalid keys, with even p, in dsa_sign().

  - Use function mpz_powm_sec() instead of mpz_powm()     (bsc#991464).

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

This update for libnettle fixes the following issues :

  - CVE-2016-6489 :

  - Reject invalid RSA keys with even modulo.

  - Check for invalid keys, with even p, in dsa_sign().

  - Use function mpz_powm_sec() instead of mpz_powm()     (bsc#991464).

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.

According to the versions of the nettle packages installed, the EulerOS installation on the remote host is affected by the following vulnerabilities :

  - Nettle is a cryptographic library that is designed to     fit easily in more or less any context: In crypto     toolkits for object-oriented languages(C++, Python,     Pike, ...), in applications like LSH or GNUPG, or even     in kernel space.

  - Secure Fix(es):

  - The ecc_256_modp function in ecc-256.c in Nettle before     3.2 does not properly handle carry propagation and     produces incorrect output in its implementation of the     P-256 NIST elliptic curve, which allows attackers to     have unspecified impact via unknown vectors, a     different vulnerability than     CVE-2015-8805.(CVE-2015-8803)

  - x86_64/ecc-384-modp.asm in Nettle before 3.2 does not     properly handle carry propagation and produces     incorrect output in its implementation of the P-384     NIST elliptic curve, which allows attackers to have     unspecified impact via unknown vectors.(CVE-2015-8804)

  - The ecc_256_modq function in ecc-256.c in Nettle before     3.2 does not properly handle carry propagation and     produces incorrect output in its implementation of the     P-256 NIST elliptic curve, which allows attackers to     have unspecified impact via unknown vectors, a     different vulnerability than     CVE-2015-8803.(CVE-2015-8805)

  - It was found that nettle's RSA and DSA decryption code     was vulnerable to cache-related side channel attacks.
    An attacker could use this flaw to recover the private     key from a co-located virtual-machine     instance.(CVE-2016-6489)

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

The remote Ubuntu 14.04 LTS / 16.04 LTS host has packages installed that are affected by a vulnerability as referenced in the USN-3193-1 advisory.

    It was discovered that Nettle incorrectly mitigated certain timing side-channel attacks. A remote attacker     could possibly use this flaw to recover private keys.

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

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

Security Fix(es) :

  - Multiple flaws were found in the way nettle implemented     elliptic curve scalar multiplication. These flaws could     potentially introduce cryptographic weaknesses into     nettle's functionality. (CVE-2015-8803, CVE-2015-8804,     CVE-2015-8805)

  - It was found that nettle's RSA and DSA decryption code     was vulnerable to cache-related side channel attacks. An     attacker could use this flaw to recover the private key     from a co-located virtual-machine instance.
    (CVE-2016-6489)

Additional Changes :

An update for nettle is now available for Red Hat Enterprise Linux 7.

Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Nettle is a cryptographic library that is designed to fit easily in almost any context: In cryptographic toolkits for object-oriented languages, such as C++, Python, or Pike, in applications like lsh or GnuPG, or even in kernel space.

Security Fix(es) :

* Multiple flaws were found in the way nettle implemented elliptic curve scalar multiplication. These flaws could potentially introduce cryptographic weaknesses into nettle's functionality. (CVE-2015-8803, CVE-2015-8804, CVE-2015-8805)

* It was found that nettle's RSA and DSA decryption code was vulnerable to cache-related side channel attacks. An attacker could use this flaw to recover the private key from a co-located virtual-machine instance. (CVE-2016-6489)

Additional Changes :

For detailed information on changes in this release, see the Red Hat Enterprise Linux 7.3 Release Notes linked from the References section.

Nettle 3.3:
https://lists.gnu.org/archive/html/info-gnu/2016-10/msg00003.html

GnuTLS 3.5.5:
https://lists.gnupg.org/pipermail/gnutls-devel/2016-October/008194.htm l

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

From Red Hat Security Advisory 2016:2582 :

An update for nettle is now available for Red Hat Enterprise Linux 7.

Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Nettle is a cryptographic library that is designed to fit easily in almost any context: In cryptographic toolkits for object-oriented languages, such as C++, Python, or Pike, in applications like lsh or GnuPG, or even in kernel space.

Security Fix(es) :

* Multiple flaws were found in the way nettle implemented elliptic curve scalar multiplication. These flaws could potentially introduce cryptographic weaknesses into nettle's functionality. (CVE-2015-8803, CVE-2015-8804, CVE-2015-8805)

* It was found that nettle's RSA and DSA decryption code was vulnerable to cache-related side channel attacks. An attacker could use this flaw to recover the private key from a co-located virtual-machine instance. (CVE-2016-6489)

Additional Changes :

For detailed information on changes in this release, see the Red Hat Enterprise Linux 7.3 Release Notes linked from the References section.

The cryptographic library nettle had a potential information leak problem reported.

CVE-2016-6489 RSA code is vulnerable to cache sharing related attacks.

For Debian 7 'Wheezy', this problems has been fixed in version 2.4-3+deb7u1.

We recommend that you upgrade your nettle packages.

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

ID	Name	Product	Family	Severity
121816	Photon OS 1.0: Nettle PHSA-2018-1.0-0119	Nessus	PhotonOS Local Security Checks	high
101016	GLSA-201706-21 : nettle: Information disclosure	Nessus	Gentoo Local Security Checks	high
100753	openSUSE Security Update : libnettle (openSUSE-2017-675)	Nessus	SuSE Local Security Checks	high
100614	SUSE SLED12 / SLES12 Security Update : libnettle (SUSE-SU-2017:1481-1)	Nessus	SuSE Local Security Checks	high
99823	EulerOS 2.0 SP1 : nettle (EulerOS-SA-2016-1061)	Nessus	Huawei Local Security Checks	critical
97050	Ubuntu 14.04 LTS / 16.04 LTS : Nettle vulnerability (USN-3193-1)	Nessus	Ubuntu Local Security Checks	high
95849	Scientific Linux Security Update : nettle on SL7.x x86_64 (20161103)	Nessus	Scientific Linux Local Security Checks	critical
95329	CentOS 7 : nettle (CESA-2016:2582)	Nessus	CentOS Local Security Checks	critical
95005	Fedora 25 : mingw-gnutls / mingw-nettle (2016-762cb57c92)	Nessus	Fedora Local Security Checks	high
94704	Oracle Linux 7 : nettle (ELSA-2016-2582)	Nessus	Oracle Linux Local Security Checks	critical
94545	RHEL 7 : nettle (RHSA-2016:2582)	Nessus	Red Hat Local Security Checks	critical
92874	Debian DLA-593-1 : nettle security update	Nessus	Debian Local Security Checks	high

Detections

Analytics

CVE-2016-6489

high

Tenable Plugins

high

high

high

high

critical

high

critical

critical

high

critical

critical

high