CVE-2018-1388 in GSKit
Summary
by MITRE
GSKit V7 may disclose side channel information via discrepencies between valid and invalid PKCS#1 padding. IBM X-Force ID: 138212.
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Analysis
by VulDB Data Team • 02/02/2021
The vulnerability identified as CVE-2018-1388 affects GSKit V7, a cryptographic toolkit developed by IBM that provides secure communication capabilities for various enterprise applications. This issue represents a significant side-channel attack vector that exploits timing discrepancies in cryptographic processing, specifically within the PKCS#1 padding validation mechanisms. The vulnerability resides in how the system handles invalid padding attempts during cryptographic operations, creating observable differences that can be exploited by attackers to extract sensitive information.
The technical flaw manifests through inconsistent processing behavior between valid and invalid PKCS#1 padding scenarios. When GSKit processes cryptographic operations with invalid padding, the system exhibits measurable timing differences compared to valid padding operations. These timing variations occur at the cryptographic algorithm level where the toolkit performs padding validation checks, creating a side-channel leakage that can be systematically analyzed. The vulnerability is particularly concerning because PKCS#1 padding is fundamental to RSA encryption and signature verification processes, making this weakness applicable across numerous cryptographic operations within the affected system.
The operational impact of this vulnerability extends beyond simple information disclosure, as it enables sophisticated attackers to perform cryptographic attacks that could compromise the security of encrypted communications. An attacker with access to the affected system can leverage the timing discrepancies to perform padding oracle attacks, potentially decrypting sensitive data or forging cryptographic signatures. This vulnerability affects the confidentiality and integrity of communications that rely on GSKit V7 for secure data handling, particularly in enterprise environments where the toolkit is used for SSL/TLS connections, digital signatures, and other cryptographic operations. The attack requires only the ability to observe timing differences and does not necessitate physical access or complex infrastructure.
Mitigation strategies for CVE-2018-1388 involve implementing constant-time cryptographic operations that eliminate timing variations during padding validation processes. Organizations should upgrade to patched versions of GSKit V7 that address the side-channel timing discrepancies in padding validation. Additionally, implementing proper cryptographic protocol design that avoids timing variations in validation processes helps prevent exploitation. The vulnerability aligns with CWE-385, which addresses timing attacks, and relates to ATT&CK technique T1005, concerning data from local system. Security teams should also consider implementing monitoring for anomalous timing behavior in cryptographic operations and ensure that all cryptographic libraries are regularly updated to address known side-channel vulnerabilities.