CVE-2016-8217 in RSA BSAFE Crypto-J
Summary
by MITRE
EMC RSA BSAFE Crypto-J versions prior to 6.2.2 has a PKCS#12 Timing Attack Vulnerability. A possible timing attack could be carried out by modifying a PKCS#12 file that has an integrity MAC for which the password is not known. An attacker could then feed the modified PKCS#12 file to the toolkit and guess the current MAC one byte at a time. This is possible because Crypto-J uses a non-constant-time method to compare the stored MAC with the calculated MAC. This vulnerability is similar to the issue described in CVE-2015-2601.
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Analysis
by VulDB Data Team • 11/04/2022
The vulnerability described in CVE-2016-8217 affects EMC RSA BSAFE Crypto-J versions prior to 6.2.2 and represents a critical timing attack flaw within the PKCS#12 file processing functionality. This vulnerability stems from the implementation of non-constant-time cryptographic operations during the verification of integrity MACs within PKCS#12 containers, creating an exploitable side-channel attack vector that allows adversaries to systematically guess password-protected MAC values through careful timing analysis.
The technical flaw manifests in the cryptographic toolkit's comparison mechanism between stored and calculated MAC values during PKCS#12 file validation. When processing a modified PKCS#12 file with an unknown password, the Crypto-J library employs a variable-time comparison function that reveals timing differences based on the correctness of guessed bytes. This timing variation occurs because the comparison operation terminates early when a correct byte is encountered, allowing an attacker to perform a byte-by-byte brute force attack against the MAC value through repeated validation attempts. The vulnerability directly maps to CWE-327, which addresses the use of insecure cryptographic algorithms and improper implementation of cryptographic operations, specifically targeting weak cryptographic implementations that leak information through timing side channels.
The operational impact of this vulnerability extends beyond simple password recovery, as it enables attackers to compromise the integrity protection mechanisms of PKCS#12 files that contain sensitive cryptographic material such as private keys and certificates. An attacker could potentially gain unauthorized access to encrypted data, impersonate legitimate users, or decrypt sensitive information that was protected using the compromised PKCS#12 containers. This vulnerability particularly affects environments where Crypto-J is used for secure key management, certificate handling, or any application requiring PKCS#12 file processing, making it a significant concern for enterprise security infrastructure.
This timing attack vulnerability aligns with techniques documented in the ATT&CK framework under the T1211 category for "Exploitation for Defense Evasion" and T1552 for "Unsecured Credentials" through the manipulation of cryptographic integrity checks. The attack pattern resembles the methodology described in CVE-2015-2601, indicating a persistent weakness in the Crypto-J implementation's approach to cryptographic comparisons. Organizations utilizing affected versions of Crypto-J should immediately implement mitigations including upgrading to version 6.2.2 or later, implementing additional access controls around PKCS#12 file handling, and monitoring for suspicious validation attempts that could indicate timing attack activities. The vulnerability demonstrates the critical importance of constant-time cryptographic implementations and proper side-channel attack resistance in security-critical applications, particularly those handling sensitive cryptographic material and authentication tokens.