ID CVE-2018-10846
Summary 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.
Vulnerable Configurations
  • cpe:2.3:a:gnu:gnutls:-:*:*:*:*:*:*:*
  • cpe:2.3:a:redhat:ansible_tower:3.3:*:*:*:*:*:*:*
  • cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
  • cpe:2.3:o:redhat:enterprise_linux_desktop:7.0:*:*:*:*:*:*:*
  • cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:*
  • cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:*
Base: 1.9 (as of 03-10-2019 - 00:03)
  • Encryption Brute Forcing
    An attacker, armed with the cipher text and the encryption algorithm used, performs an exhaustive (brute force) search on the key space to determine the key that decrypts the cipher text to obtain the plaintext.
  • Creating a Rogue Certificate Authority Certificate
    An attacker exploits a weakness in the MD5 hash algorithm (weak collision resistance) to generate a certificate signing request (CSR) that contains collision blocks in the "to be signed" part. The attacker specially crafts two different, but valid X.509 certificates that when hashed with the MD5 algorithm would yield the same value. The attacker then sends the CSR for one of the certificates to the Certification Authority which uses the MD5 hashing algorithm. That request is completely valid and the Certificate Authority issues an X.509 certificate to the attacker which is signed with its private key. An attacker then takes that signed blob and inserts it into another X.509 certificate that the attacker generated. Due to the MD5 collision, both certificates, though different, hash to the same value and so the signed blob works just as well in the second certificate. The net effect is that the attackers' second X.509 certificate, which the Certification Authority has never seen, is now signed and validated by that Certification Authority. To make the attack more interesting, the second certificate could be not just a regular certificate, but rather itself a signing certificate. Thus the attacker is able to start their own Certification Authority that is anchored in its root of trust in the legitimate Certification Authority that has signed the attackers' first X.509 certificate. If the original Certificate Authority was accepted by default by browsers, so will now the Certificate Authority set up by the attacker and of course any certificates that it signs. So the attacker is now able to generate any SSL certificates to impersonate any web server, and the user's browser will not issue any warning to the victim. This can be used to compromise HTTPS communications and other types of systems where PKI and X.509 certificates may be used (e.g., VPN, IPSec) .
  • Signature Spoof
    An attacker generates a message or datablock that causes the recipient to believe that the message or datablock was generated and cryptographically signed by an authoritative or reputable source, misleading a victim or victim operating system into performing malicious actions.
  • Cryptanalysis
    Cryptanalysis is a process of finding weaknesses in cryptographic algorithms and using these weaknesses to decipher the ciphertext without knowing the secret key (instance deduction). Sometimes the weakness is not in the cryptographic algorithm itself, but rather in how it is applied that makes cryptanalysis successful. An attacker may have other goals as well, such as: 1. Total Break - Finding the secret key 2. Global Deduction - Finding a functionally equivalent algorithm for encryption and decryption that does not require knowledge of the secret key. 3. Information Deduction - Gaining some information about plaintexts or ciphertexts that was not previously known 4. Distinguishing Algorithm - The attacker has the ability to distinguish the output of the encryption (ciphertext) from a random permutation of bits The goal of the attacker performing cryptanalysis will depend on the specific needs of the attacker in a given attack context. In most cases, if cryptanalysis is successful at all, an attacker will not be able to go past being able to deduce some information about the plaintext (goal 3). However, that may be sufficient for an attacker, depending on the context.
assigner via4
cvss-vector via4 AV:L/AC:M/Au:N/C:P/I:N/A:N
redhat via4
  • bugzilla
    id 1582574
    title PRIME + PROBE cache-based side channel attack can lead to plaintext recovery
    • OR
      • comment Red Hat Enterprise Linux 7 Client is installed
        oval oval:com.redhat.rhba:tst:20150364001
      • comment Red Hat Enterprise Linux 7 Server is installed
        oval oval:com.redhat.rhba:tst:20150364002
      • comment Red Hat Enterprise Linux 7 Workstation is installed
        oval oval:com.redhat.rhba:tst:20150364003
      • comment Red Hat Enterprise Linux 7 ComputeNode is installed
        oval oval:com.redhat.rhba:tst:20150364004
    • OR
      • AND
        • comment gnutls is earlier than 0:3.3.29-8.el7
          oval oval:com.redhat.rhsa:tst:20183050011
        • comment gnutls is signed with Red Hat redhatrelease2 key
          oval oval:com.redhat.rhsa:tst:20120429006
      • AND
        • comment gnutls-c++ is earlier than 0:3.3.29-8.el7
          oval oval:com.redhat.rhsa:tst:20183050007
        • comment gnutls-c++ is signed with Red Hat redhatrelease2 key
          oval oval:com.redhat.rhsa:tst:20140684010
      • AND
        • comment gnutls-dane is earlier than 0:3.3.29-8.el7
          oval oval:com.redhat.rhsa:tst:20183050013
        • comment gnutls-dane is signed with Red Hat redhatrelease2 key
          oval oval:com.redhat.rhsa:tst:20140684008
      • AND
        • comment gnutls-devel is earlier than 0:3.3.29-8.el7
          oval oval:com.redhat.rhsa:tst:20183050009
        • comment gnutls-devel is signed with Red Hat redhatrelease2 key
          oval oval:com.redhat.rhsa:tst:20120429010
      • AND
        • comment gnutls-utils is earlier than 0:3.3.29-8.el7
          oval oval:com.redhat.rhsa:tst:20183050005
        • comment gnutls-utils is signed with Red Hat redhatrelease2 key
          oval oval:com.redhat.rhsa:tst:20120429008
    id RHSA-2018:3050
    released 2018-10-30
    severity Moderate
    title RHSA-2018:3050: gnutls security, bug fix, and enhancement update (Moderate)
  • rhsa
    id RHSA-2018:3505
  • gnutls-0:3.3.29-8.el7
  • gnutls-c++-0:3.3.29-8.el7
  • gnutls-dane-0:3.3.29-8.el7
  • gnutls-devel-0:3.3.29-8.el7
  • gnutls-utils-0:3.3.29-8.el7
refmap via4
bid 105138
mlist [debian-lts-announce] 20181030 [SECURITY] [DLA 1560-1] gnutls28 security update
ubuntu USN-3999-1
vulnerable_product via4
  • cpe:2.3:a:gnu:gnutls:-:*:*:*:*:*:*:*
  • cpe:2.3:a:redhat:ansible_tower:3.3:*:*:*:*:*:*:*
  • cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
  • cpe:2.3:o:redhat:enterprise_linux_desktop:7.0:*:*:*:*:*:*:*
  • cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:*
  • cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:*
Last major update 03-10-2019 - 00:03
Published 22-08-2018 - 13:29
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