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.

The updated packages fix security vulnerabilities:

It was found that the GnuTLS implementation of HMAC-SHA-256 and HMAC-SHA-384 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-2018-10844, CVE-2018-10845).

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 (CVE-2018-10846).

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)

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)

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)

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)

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)