A cache-based side channel in GnuTLS implementation that leads to plain text recovery in cross-VM attack setting was found. An attacker could use a combination of "Just in Time" Prime+probe attack in combination with Lucky-13 attack to recover plain text using crafted packets.

https://lists.gnupg.org/pipermail/gnutls-help/2020-March/004642.html

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.

According to the version of the gnutls packages installed, the EulerOS installation on the remote host is affected by the following vulnerability :

  - A cache-based side channel attack was found in the way     GnuTLS implements CBC-mode cipher suites. An attacker     could use a combination of 'Just in Time' Prime+probe     and Lucky-13 attacks to recover plain text in a     cross-VM attack scenario.(CVE-2018-10846)

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 NewStart CGSL host, running version CORE 5.04 / MAIN 5.04, has gnutls packages installed that are affected by multiple vulnerabilities:

  - It was found that GnuTLS's implementation of HMAC-     SHA-256 was vulnerable to Lucky Thirteen-style attack. A     remote attacker could use this flaw to conduct     distinguishing attacks and plain text recovery attacks     via statistical analysis of timing data using crafted     packets. (CVE-2018-10844)

  - It was found that GnuTLS's implementation of HMAC-     SHA-384 was vulnerable to a Lucky Thirteen-style attack.
    A remote attacker could use this flaw to conduct     distinguishing attacks and plain text recovery attacks     via statistical analysis of timing data using crafted     packets. (CVE-2018-10845)

  - A cache-based side channel attack was found in the way     GnuTLS implements CBC-mode cipher suites. An attacker     could use a combination of Just in Time Prime+probe     and Lucky-13 attacks to recover plain text in a cross-VM     attack scenario. (CVE-2018-10846)

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

According to the version of the gnutls packages installed, the EulerOS Virtualization for ARM 64 installation on the remote host is affected by the following vulnerability :

  - A cache-based side channel attack was found in the way     GnuTLS implements CBC-mode cipher suites. An attacker     could use a combination of 'Just in Time' Prime+probe     and Lucky-13 attacks to recover plain text in a     cross-VM attack scenario.(CVE-2018-10846)

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.

Eyal Ronen, Kenneth G. Paterson, and Adi Shamir discovered that GnuTLS was vulnerable to a timing side-channel attack known as the 'Lucky Thirteen' issue. A remote attacker could possibly use this issue to perform plaintext-recovery attacks via analysis of timing data. This issue only affected Ubuntu 16.04 LTS and Ubuntu 18.04 LTS.
(CVE-2018-10844, CVE-2018-10845, CVE-2018-10846)

Tavis Ormandy discovered that GnuTLS incorrectly handled memory when verifying certain X.509 certificates. A remote attacker could use this issue to cause GnuTLS to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 18.04 LTS, Ubuntu 18.10, and Ubuntu 19.04. (CVE-2019-3829)

It was discovered that GnuTLS incorrectly handled certain post-handshake messages. A remote attacker could use this issue to cause GnuTLS to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 18.10 and Ubuntu 19.04. (CVE-2019-3836).

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

This update for gnutls fixes the following security issues :

  - Improved mitigations against Lucky 13 class of attacks

  - CVE-2018-10846: 'Just in Time' PRIME + PROBE cache-based     side channel attack can lead to plaintext recovery     (bsc#1105460)

  - CVE-2018-10845: HMAC-SHA-384 vulnerable to Lucky     thirteen attack due to use of wrong constant     (bsc#1105459)

  - CVE-2018-10844: HMAC-SHA-256 vulnerable to Lucky     thirteen attack due to not enough dummy function calls     (bsc#1105437)

  - CVE-2017-10790: The _asn1_check_identifier function in     Libtasn1 caused a NULL pointer dereference and crash     (bsc#1047002)

This update was imported from the SUSE:SLE-15:Update update project.

This update for gnutls fixes the following security issues :

Improved mitigations against Lucky 13 class of attacks

CVE-2018-10846: 'Just in Time' PRIME + PROBE cache-based side channel attack can lead to plaintext recovery (bsc#1105460)

CVE-2018-10845: HMAC-SHA-384 vulnerable to Lucky thirteen attack due to use of wrong constant (bsc#1105459)

CVE-2018-10844: HMAC-SHA-256 vulnerable to Lucky thirteen attack due to not enough dummy function calls (bsc#1105437)

CVE-2017-10790: The _asn1_check_identifier function in Libtasn1 caused a NULL pointer dereference and crash (bsc#1047002)

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.

An update for gnutls 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.

The gnutls packages provide the GNU Transport Layer Security (GnuTLS) library, which implements cryptographic algorithms and protocols such as SSL, TLS, and DTLS.

The following packages have been upgraded to a later upstream version:
gnutls (3.3.29). (BZ#1561481)

Security Fix(es) :

* gnutls: HMAC-SHA-256 vulnerable to Lucky thirteen attack due to not enough dummy function calls (CVE-2018-10844)

* gnutls: HMAC-SHA-384 vulnerable to Lucky thirteen attack due to use of wrong constant (CVE-2018-10845)

* gnutls: 'Just in Time' PRIME + PROBE cache-based side channel attack can lead to plaintext recovery (CVE-2018-10846)

For more details about the security issue(s), including the impact, a CVSS score, and other related information, refer to the CVE page(s) listed in the References section.

Additional Changes :

For detailed information on changes in this release, see the Red Hat Enterprise Linux 7.6 Release Notes linked from the References section.

It was found that GnuTLS's implementation of HMAC-SHA-256 was vulnerable to Lucky Thirteen-style attack. A remote attacker could use this flaw to conduct distinguishing attacks and plain text recovery attacks via statistical analysis of timing data using crafted packets.(CVE-2018-10844)

It was found that GnuTLS's implementation of HMAC-SHA-384 was vulnerable to a Lucky Thirteen-style attack. A remote attacker could use this flaw to conduct distinguishing attacks and plain text recovery attacks via statistical analysis of timing data using crafted packets.(CVE-2018-10845)

A cache-based side channel attack was found in the way GnuTLS implements CBC-mode cipher suites. An attacker could use a combination of 'Just in Time' Prime+probe and Lucky-13 attacks to recover plain text in a cross-VM attack scenario.(CVE-2018-10846)

Security Fix(es) :

  - gnutls: HMAC-SHA-256 vulnerable to Lucky thirteen attack     due to not enough dummy function calls (CVE-2018-10844)

  - gnutls: HMAC-SHA-384 vulnerable to Lucky thirteen attack     due to use of wrong constant (CVE-2018-10845)

  - gnutls: 'Just in Time' PRIME + PROBE cache-based side     channel attack can lead to plaintext recovery     (CVE-2018-10846)

From Red Hat Security Advisory 2018:3050 :

An update for gnutls 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.

The gnutls packages provide the GNU Transport Layer Security (GnuTLS) library, which implements cryptographic algorithms and protocols such as SSL, TLS, and DTLS.

The following packages have been upgraded to a later upstream version:
gnutls (3.3.29). (BZ#1561481)

Security Fix(es) :

* gnutls: HMAC-SHA-256 vulnerable to Lucky thirteen attack due to not enough dummy function calls (CVE-2018-10844)

* gnutls: HMAC-SHA-384 vulnerable to Lucky thirteen attack due to use of wrong constant (CVE-2018-10845)

* gnutls: 'Just in Time' PRIME + PROBE cache-based side channel attack can lead to plaintext recovery (CVE-2018-10846)

For more details about the security issue(s), including the impact, a CVSS score, and other related information, refer to the CVE page(s) listed in the References section.

Additional Changes :

For detailed information on changes in this release, see the Red Hat Enterprise Linux 7.6 Release Notes linked from the References section.

The remote Redhat Enterprise Linux 7 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2018:3050 advisory.

  - gnutls: HMAC-SHA-256 vulnerable to Lucky thirteen attack due to not enough dummy function calls     (CVE-2018-10844)

  - gnutls: HMAC-SHA-384 vulnerable to Lucky thirteen attack due to use of wrong constant (CVE-2018-10845)

  - gnutls: Just in Time PRIME + PROBE cache-based side channel attack can lead to plaintext recovery     (CVE-2018-10846)

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

A set of vulnerabilities was discovered in GnuTLS which allowed attackers to do plain text recovery on TLS connections with certain cipher types.

CVE-2018-10844

It was found that the GnuTLS implementation of HMAC-SHA-256 was vulnerable to a Lucky thirteen style attack. Remote attackers could use this flaw to conduct distinguishing attacks and plaintext-recovery attacks via statistical analysis of timing data using crafted packets.

CVE-2018-10845

It was found that the GnuTLS implementation of HMAC-SHA-384 was vulnerable to a Lucky thirteen style attack. Remote attackers could use this flaw to conduct distinguishing attacks and plain text recovery attacks via statistical analysis of timing data using crafted packets.

CVE-2018-10846

A cache-based side channel in GnuTLS implementation that leads to plain text recovery in cross-VM attack setting was found. An attacker could use a combination of 'Just in Time' Prime+probe attack in combination with Lucky-13 attack to recover plain text using crafted packets.

For Debian 8 'Jessie', these problems have been fixed in version 3.3.30-0+deb8u1. It was found to be more practical to update to the latest upstream version of the 3.3.x branch since upstream's fixes were rather invasive and required cipher list changes anyways. This will facilitate future LTS updates as well.

This change therefore also includes the following major policy changes, as documented in the NEWS file :

  - ARCFOUR (RC4) and SSL 3.0 are no longer included in the     default priorities list. Those have to be explicitly     enabled, e.g., with a string like 'NORMAL:+ARCFOUR-128'     or 'NORMAL:+VERS-SSL3.0', respectively.

  - The ciphers utilizing HMAC-SHA384 and SHA256 have been     removed from the default priority strings. They are not     necessary for compatibility or other purpose and provide     no advantage over their SHA1 counter-parts, as they all     depend on the legacy TLS CBC block mode.

  - Follow closely RFC5280 recommendations and use UTCTime     for dates prior to 2050.

  - Require strict DER encoding for certificates, OCSP     requests, private keys, CRLs and certificate requests,     in order to reduce issues due to the complexity of BER     rules.

  - Refuse to import v1 or v2 certificates that contain     extensions.

API and ABI compatibility is retained, however, although new symbols have been added. Many bugfixes are also included in the upload. See the provided upstream changelog for more details.

We recommend that you upgrade your gnutls28 packages and do not expect significant breakage.

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.

This update for gnutls fixes the following issues :

This update for gnutls fixes the following issues :

Security issues fixed :

Improved mitigations against Lucky 13 class of attacks

'Just in Time' PRIME + PROBE cache-based side channel attack can lead to plaintext recovery (CVE-2018-10846, bsc#1105460)

HMAC-SHA-384 vulnerable to Lucky thirteen attack due to use of wrong constant (CVE-2018-10845, bsc#1105459)

HMAC-SHA-256 vulnerable to Lucky thirteen attack due to not enough dummy function calls (CVE-2018-10844, bsc#1105437)

The _asn1_check_identifier function in Libtasn1 caused a NULL pointer dereference and crash (CVE-2017-10790, bsc#1047002)

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.

This update for gnutls fixes the following issues :

Security issues fixed :

  - Improved mitigations against Lucky 13 class of attacks

  - CVE-2018-10846: 'Just in Time' PRIME + PROBE cache-based     side channel attack can lead to plaintext recovery     (bsc#1105460)

  - CVE-2018-10845: HMAC-SHA-384 vulnerable to Lucky     thirteen attack due to use of wrong constant     (bsc#1105459)

  - CVE-2018-10844: HMAC-SHA-256 vulnerable to Lucky     thirteen attack due to not enough dummy function calls     (bsc#1105437)

  - CVE-2017-10790: The _asn1_check_identifier function in     Libtasn1 caused a NULL pointer dereference and crash     (bsc#1047002)

This update was imported from the SUSE:SLE-12-SP3:Update update project.

This update for gnutls fixes the following issues :

Security issues fixed :

Improved mitigations against Lucky 13 class of attacks

  - 'Just in Time' PRIME + PROBE cache-based side channel     attack can lead to plaintext recovery (CVE-2018-10846,     bsc#1105460)

  - HMAC-SHA-384 vulnerable to Lucky thirteen attack due to     use of wrong constant (CVE-2018-10845, bsc#1105459)

  - HMAC-SHA-256 vulnerable to Lucky thirteen attack due to     not enough dummy function calls (CVE-2018-10844,     bsc#1105437)

The _asn1_check_identifier function in Libtasn1 caused a NULL pointer dereference and crash (CVE-2017-10790, bsc#1047002)

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.

ID	Name	Product	Family	Severity
136416	Fedora 31 : mingw-gnutls (2020-d14280a6e8)	Nessus	Fedora Local Security Checks	high
129209	EulerOS 2.0 SP3 : gnutls (EulerOS-SA-2019-2016)	Nessus	Huawei Local Security Checks	medium
127268	NewStart CGSL CORE 5.04 / MAIN 5.04 : gnutls Multiple Vulnerabilities (NS-SA-2019-0068)	Nessus	NewStart CGSL Local Security Checks	medium
126870	EulerOS 2.0 SP2 : gnutls (EulerOS-SA-2019-1743)	Nessus	Huawei Local Security Checks	medium
126535	EulerOS Virtualization for ARM 64 3.0.2.0 : gnutls (EulerOS-SA-2019-1693)	Nessus	Huawei Local Security Checks	medium
126418	EulerOS 2.0 SP5 : gnutls (EulerOS-SA-2019-1676)	Nessus	Huawei Local Security Checks	medium
125622	Ubuntu 16.04 LTS / 18.04 LTS : GnuTLS vulnerabilities (USN-3999-1)	Nessus	Ubuntu Local Security Checks	medium
123319	openSUSE Security Update : gnutls (openSUSE-2019-746)	Nessus	SuSE Local Security Checks	medium
120112	SUSE SLED15 / SLES15 Security Update : gnutls (SUSE-SU-2018:2930-1)	Nessus	SuSE Local Security Checks	medium
119690	CentOS 7 : gnutls (CESA-2018:3050)	Nessus	CentOS Local Security Checks	medium
119503	Amazon Linux 2 : gnutls (ALAS-2018-1120)	Nessus	Amazon Linux Local Security Checks	medium
119184	Scientific Linux Security Update : gnutls on SL7.x x86_64 (20181030)	Nessus	Scientific Linux Local Security Checks	medium
118764	Oracle Linux 7 : gnutls (ELSA-2018-3050)	Nessus	Oracle Linux Local Security Checks	medium
118516	RHEL 7 : gnutls (RHSA-2018:3050)	Nessus	Red Hat Local Security Checks	medium
118504	Debian DLA-1560-1 : gnutls28 security update	Nessus	Debian Local Security Checks	medium
118292	SUSE SLES12 Security Update : gnutls (SUSE-SU-2018:2825-2)	Nessus	SuSE Local Security Checks	medium
117897	openSUSE Security Update : gnutls (openSUSE-2018-1092)	Nessus	SuSE Local Security Checks	high
117792	openSUSE Security Update : gnutls (openSUSE-2018-1049)	Nessus	SuSE Local Security Checks	high
117702	SUSE SLED12 / SLES12 Security Update : gnutls (SUSE-SU-2018:2842-1)	Nessus	SuSE Local Security Checks	medium
117696	SUSE SLES12 Security Update : gnutls (SUSE-SU-2018:2825-1)	Nessus	SuSE Local Security Checks	medium

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