ID CVE-2016-3099
Summary mod_ns in Red Hat Enterprise Linux Desktop 7, Red Hat Enterprise Linux HPC Node 7, Red Hat Enterprise Linux Server 7, and Red Hat Enterprise Linux Workstation 7 allows remote attackers to force the use of ciphers that were not intended to be enabled.
References
Vulnerable Configurations
  • cpe:2.3:o:redhat:enterprise_linux_desktop:7.0:*:*:*:*:*:*:*
    cpe:2.3:o:redhat:enterprise_linux_desktop:7.0:*:*:*:*:*:*:*
  • cpe:2.3:o:redhat:enterprise_linux_hpc_node:7.0:*:*:*:*:*:*:*
    cpe:2.3:o:redhat:enterprise_linux_hpc_node:7.0:*:*:*:*:*:*:*
  • cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:*
    cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:*
  • cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:*
    cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:*
CVSS
Base: 5.0 (as of 16-06-2017 - 14:23)
Impact:
Exploitability:
CWE CWE-327
CAPEC
  • 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.
Access
VectorComplexityAuthentication
NETWORK LOW NONE
Impact
ConfidentialityIntegrityAvailability
NONE PARTIAL NONE
cvss-vector via4 AV:N/AC:L/Au:N/C:N/I:P/A:N
redhat via4
advisories
bugzilla
id 1364560
title mod_nss leaks semaphores
oval
AND
  • comment mod_nss is earlier than 0:1.0.14-7.el7
    oval oval:com.redhat.rhsa:tst:20162602005
  • comment mod_nss is signed with Red Hat redhatrelease2 key
    oval oval:com.redhat.rhba:tst:20111656006
  • 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
rhsa
id RHSA-2016:2602
released 2016-11-03
severity Low
title RHSA-2016:2602: mod_nss security, bug fix, and enhancement update (Low)
rpms mod_nss-0:1.0.14-7.el7
refmap via4
confirm https://bugzilla.redhat.com/show_bug.cgi?id=1319052
fedora
  • FEDORA-2016-1eaaf1ed0f
  • FEDORA-2016-85e9f2e3cd
  • FEDORA-2016-8b28358b72
Last major update 16-06-2017 - 14:23
Published 08-06-2017 - 19:29
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