GnuTLS 3.6.x before 3.6.14 uses incorrect cryptography for encrypting a session ticket (a loss of confidentiality in TLS 1.2, and an authentication bypass in TLS 1.3). The earliest affected version is 3.6.4 (2018-09-24) because of an error in a 2018-09-18 commit. Until the first key rotation, the TLS server always uses wrong data in place of an encryption key derived from an application.

The remote CentOS Linux 8 host has packages installed that are affected by a vulnerability as referenced in the CESA-2020:2637 advisory.

  - gnutls: session resumption works without master key allowing MITM (CVE-2020-13777)

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 versions of the gnutls packages installed, the EulerOS Virtualization for ARM 64 installation on the remote host is affected by the following vulnerabilities :

  - GnuTLS 3.6.x before 3.6.13 uses incorrect cryptography     for DTLS. The earliest affected version is 3.6.3     (2018-07-16) because of an error in a 2017-10-06     commit. The DTLS client always uses 32 '\0' bytes     instead of a random value, and thus contributes no     randomness to a DTLS negotiation. This breaks the     security guarantees of the DTLS     protocol.(CVE-2020-11501)

  - GnuTLS 3.6.x before 3.6.14 uses incorrect cryptography     for encrypting a session ticket (a loss of     confidentiality in TLS 1.2, and an authentication     bypass in TLS 1.3). The earliest affected version is     3.6.4 (2018-09-24) because of an error in a 2018-09-18     commit. Until the first key rotation, the TLS server     always uses wrong data in place of an encryption key     derived from an application.(CVE-2020-13777)

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.

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

  - GnuTLS 3.6.x before 3.6.14 uses incorrect cryptography     for encrypting a session ticket (a loss of     confidentiality in TLS 1.2, and an authentication     bypass in TLS 1.3). The earliest affected version is     3.6.4 (2018-09-24) because of an error in a 2018-09-18     commit. Until the first key rotation, the TLS server     always uses wrong data in place of an encryption key     derived from an application.(CVE-2020-13777)

  - GnuTLS 3.6.x before 3.6.13 uses incorrect cryptography     for DTLS. The earliest affected version is 3.6.3     (2018-07-16) because of an error in a 2017-10-06     commit. The DTLS client always uses 32 '\0' bytes     instead of a random value, and thus contributes no     randomness to a DTLS negotiation. This breaks the     security guarantees of the DTLS     protocol.(CVE-2020-11501)

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 Oracle Linux 8 host has packages installed that are affected by a vulnerability as referenced in the ELSA-2020-2637 advisory.

    [3.6.8-11]
    - Fix CVE-2020-13777 (#1844147)

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

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

An update of the gnutls package has been released.

The remote Redhat Enterprise Linux 8 host has packages installed that are affected by a vulnerability as referenced in the RHSA-2020:2637 advisory.

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

    Security Fix(es):

    * gnutls: session resumption works without master key allowing MITM (CVE-2020-13777)

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

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

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

The remote Redhat Enterprise Linux 8 host has packages installed that are affected by a vulnerability as referenced in the RHSA-2020:2638 advisory.

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

    Security Fix(es):

    * gnutls: session resumption works without master key allowing MITM (CVE-2020-13777)

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

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

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

The remote Redhat Enterprise Linux 8 host has packages installed that are affected by a vulnerability as referenced in the RHSA-2020:2639 advisory.

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

    Security Fix(es):

    * gnutls: session resumption works without master key allowing MITM (CVE-2020-13777)

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

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

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

This update for gnutls fixes the following issues :

CVE-2020-13777: Fixed an insecure session ticket key construction which could have made the TLS server to not bind the session ticket encryption key with a value supplied by the application until the initial key rotation, allowing an attacker to bypass authentication in TLS 1.3 and recover previous conversations in TLS 1.2 (bsc#1172506).

Fixed an improper handling of certificate chain with cross-signed intermediate CA certificates (bsc#1172461).

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.

Update to upstream 3.6.14 release, and security fix for CVE-2020-13777.

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.

Update to upstream 3.6.14 release, and security fix for CVE-2020-13777.

----

  - Fix certificate chain validation involving the expired     'AddTrust External Root'.

  - Disable RSA blinding during FIPS self-tests to avoid     hanging if there is not enough entropy for `getrandom()`

  - Add `--waitresumption` option to `gnutls-cli` to force     the client to wait for resumption data (new session     ticket) under TLS 1.3

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.

This update for gnutls fixes the following issues :

  - CVE-2020-13777: Fixed an insecure session ticket key     construction which could have made the TLS server to not     bind the session ticket encryption key with a value     supplied by the application until the initial key     rotation, allowing an attacker to bypass authentication     in TLS 1.3 and recover previous conversations in TLS 1.2     (bsc#1172506).

  - Fixed an improper handling of certificate chain with     cross-signed intermediate CA certificates (bsc#1172461).

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

The remote host is affected by the vulnerability described in GLSA-202006-01 (GnuTLS: Information disclosure)

    A flaw was reported in the TLS session ticket key construction in       GnuTLS.
  Impact :

    A remote attacker could recover previous conversations in TLS 1.2 and       obtain sensitive information or conduct a man-in-the-middle attack to       bypass authentication in TLS 1.3.
  Workaround :

    There is no known workaround at this time.

The remote Ubuntu 20.04 LTS host has packages installed that are affected by a vulnerability as referenced in the USN-4384-1 advisory.

    It was discovered that GnuTLS incorrectly handled session ticket encryption keys. A remote attacker could     possibly use this issue to bypass authentication or recover sensitive information.

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.

A flaw was reported in the TLS session ticket key construction in GnuTLS, a library implementing the TLS and SSL protocols. The flaw caused the TLS server to not securely construct a session ticket encryption key considering the application supplied secret, allowing a man-in-the-middle attacker to bypass authentication in TLS 1.3 and recover previous conversations in TLS 1.2.

The GnuTLS project reports :

It was found that GnuTLS 3.6.4 introduced a regression in the TLS protocol implementation. This caused the TLS server to not securely construct a session ticket encryption key considering the application supplied secret, allowing a MitM attacker to bypass authentication in TLS 1.3 and recover previous conversations in TLS 1.2.

ID	Name	Product	Family	Severity
145970	CentOS 8 : gnutls (CESA-2020:2637)	Nessus	CentOS Local Security Checks	high
140002	EulerOS Virtualization for ARM 64 3.0.6.0 : gnutls (EulerOS-SA-2020-1899)	Nessus	Huawei Local Security Checks	high
139133	EulerOS 2.0 SP8 : gnutls (EulerOS-SA-2020-1803)	Nessus	Huawei Local Security Checks	high
137769	Oracle Linux 8 : gnutls (ELSA-2020-2637)	Nessus	Oracle Linux Local Security Checks	high
137722	Photon OS 3.0: Gnutls PHSA-2020-3.0-0103	Nessus	PhotonOS Local Security Checks	high
137711	RHEL 8 : gnutls (RHSA-2020:2637)	Nessus	Red Hat Local Security Checks	high
137707	RHEL 8 : gnutls (RHSA-2020:2638)	Nessus	Red Hat Local Security Checks	high
137669	RHEL 8 : gnutls (RHSA-2020:2639)	Nessus	Red Hat Local Security Checks	high
137607	SUSE SLED15 / SLES15 Security Update : gnutls (SUSE-SU-2020:1584-1)	Nessus	SuSE Local Security Checks	high
137434	Fedora 31 : mingw-gnutls (2020-ea11cb5ccc)	Nessus	Fedora Local Security Checks	high
137426	Fedora 31 : gnutls (2020-76b705bb63)	Nessus	Fedora Local Security Checks	high
137424	Fedora 32 : mingw-gnutls (2020-4f78f122a3)	Nessus	Fedora Local Security Checks	high
137350	openSUSE Security Update : gnutls (openSUSE-2020-790)	Nessus	SuSE Local Security Checks	high
137288	GLSA-202006-01 : GnuTLS: Information disclosure	Nessus	Gentoo Local Security Checks	high
137232	Ubuntu 20.04 LTS : GnuTLS vulnerability (USN-4384-1)	Nessus	Ubuntu Local Security Checks	high
137211	Fedora 32 : gnutls (2020-0cce3578e2)	Nessus	Fedora Local Security Checks	high
137209	Debian DSA-4697-1 : gnutls28 - security update	Nessus	Debian Local Security Checks	high
137169	FreeBSD : GnuTLS -- flaw in TLS session ticket key construction (ef5b4f5f-a658-11ea-80d7-001cc0382b2f)	Nessus	FreeBSD Local Security Checks	high

Detections

Analytics

CVE-2020-13777

high

Tenable Plugins

high

high

high

high

high

high

high

high

high

high

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high