Vulnerabilities > CVE-2022-1434 - Use of a Broken or Risky Cryptographic Algorithm vulnerability in multiple products
Summary
The OpenSSL 3.0 implementation of the RC4-MD5 ciphersuite incorrectly uses the AAD data as the MAC key. This makes the MAC key trivially predictable. An attacker could exploit this issue by performing a man-in-the-middle attack to modify data being sent from one endpoint to an OpenSSL 3.0 recipient such that the modified data would still pass the MAC integrity check. Note that data sent from an OpenSSL 3.0 endpoint to a non-OpenSSL 3.0 endpoint will always be rejected by the recipient and the connection will fail at that point. Many application protocols require data to be sent from the client to the server first. Therefore, in such a case, only an OpenSSL 3.0 server would be impacted when talking to a non-OpenSSL 3.0 client. If both endpoints are OpenSSL 3.0 then the attacker could modify data being sent in both directions. In this case both clients and servers could be affected, regardless of the application protocol. Note that in the absence of an attacker this bug means that an OpenSSL 3.0 endpoint communicating with a non-OpenSSL 3.0 endpoint will fail to complete the handshake when using this ciphersuite. The confidentiality of data is not impacted by this issue, i.e. an attacker cannot decrypt data that has been encrypted using this ciphersuite - they can only modify it. In order for this attack to work both endpoints must legitimately negotiate the RC4-MD5 ciphersuite. This ciphersuite is not compiled by default in OpenSSL 3.0, and is not available within the default provider or the default ciphersuite list. This ciphersuite will never be used if TLSv1.3 has been negotiated. In order for an OpenSSL 3.0 endpoint to use this ciphersuite the following must have occurred: 1) OpenSSL must have been compiled with the (non-default) compile time option enable-weak-ssl-ciphers 2) OpenSSL must have had the legacy provider explicitly loaded (either through application code or via configuration) 3) The ciphersuite must have been explicitly added to the ciphersuite list 4) The libssl security level must have been set to 0 (default is 1) 5) A version of SSL/TLS below TLSv1.3 must have been negotiated 6) Both endpoints must negotiate the RC4-MD5 ciphersuite in preference to any others that both endpoints have in common Fixed in OpenSSL 3.0.3 (Affected 3.0.0,3.0.1,3.0.2).
Vulnerable Configurations
| Part | Description | Count |
|---|---|---|
| Application | 23 | |
| Application | 8 | |
| OS | Netapp
| 17 |
| Hardware | 17 |
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (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.