Free and open-source vulnerability scanner

Mageni eases for you the vulnerability scanning, assessment, and management process. It is free and open-source.

Install Now

Available for macOS, Windows, and Linux

App screenshot

Debian LTS Advisory ([SECURITY] [DLA 1560-1] gnutls28 security update)

Information

Severity

Severity

Medium

Family

Family

Debian Local Security Checks

CVSSv2 Base

CVSSv2 Base

4.3

CVSSv2 Vector

CVSSv2 Vector

AV:N/AC:M/Au:N/C:P/I:N/A:N

Solution Type

Solution Type

Vendor Patch

Created

Created

4 years ago

Modified

Modified

3 years ago

Summary

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.

Affected Software

Affected Software

gnutls28 on Debian Linux

Detection Method

Detection Method

This check tests the installed software version using the apt package manager.

Solution

Solution

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.

Common Vulnerabilities and Exposures (CVE)