CVE-2019-16762 in slpjs
Summary
by MITRE
A specially crafted Bitcoin script can cause a discrepancy between the specified SLP consensus rules and the validation result of the slpjs npm package. An attacker could create a specially crafted Bitcoin script in order to cause a hard-fork from the SLP consensus. Affected users can upgrade to any version >= 0.21.4.
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Analysis
by VulDB Data Team • 02/20/2024
This vulnerability resides in the slpjs npm package, which implements the Simple Ledger Protocol (SLP) for Bitcoin transactions. The flaw manifests when processing specially crafted Bitcoin scripts that create inconsistencies between the intended SLP consensus rules and the actual validation behavior of the slpjs library. Such discrepancies can potentially enable attackers to manipulate transaction validation outcomes in ways that deviate from established SLP standards, creating opportunities for protocol manipulation. The vulnerability specifically targets the script validation logic within the npm package, where the discrepancy between expected and actual behavior could be exploited to cause unintended transaction processing outcomes. This represents a critical issue for any system relying on slpjs for SLP transaction validation, as it undermines the integrity of the consensus mechanisms that govern SLP-compliant transactions.
The technical implementation of this vulnerability stems from how the slpjs library processes Bitcoin scripts that contain specific patterns or structures that trigger inconsistent validation behavior. When these crafted scripts are processed, the library's validation logic fails to properly align with the established SLP consensus rules, creating a scenario where the same transaction could be interpreted differently depending on whether it's validated through the vulnerable library or through compliant implementations. This inconsistency occurs at the core validation layer where Bitcoin script execution meets SLP protocol requirements, allowing for potential exploitation through carefully constructed transaction inputs. The vulnerability essentially creates a path where malicious actors can craft transactions that appear valid to the vulnerable library but would be rejected by proper SLP consensus implementations, potentially leading to transaction malleability issues.
The operational impact of this vulnerability extends beyond simple validation failures, as it creates a potential pathway for hard-fork scenarios within the SLP ecosystem. If exploited successfully, an attacker could cause a divergence between what the slpjs library validates as legitimate and what the broader SLP consensus considers valid, potentially leading to transaction disputes or even network fragmentation. The vulnerability affects any application or service that relies on slpjs for SLP transaction processing, making it particularly concerning for wallet providers, exchanges, and blockchain explorers that depend on accurate transaction validation. Users operating systems where this vulnerability exists face risks of transaction processing failures, potential fund loss, or manipulation of transaction outcomes that could compromise the integrity of their SLP-based operations. The risk is amplified because SLP transactions are typically immutable once confirmed, meaning any exploitation could have permanent consequences for affected transactions.
The recommended mitigation strategy involves immediate upgrading to slpjs version 0.21.4 or later, which contains fixes addressing the script validation inconsistencies. Organizations should conduct thorough testing of their applications after upgrading to ensure no regression issues occur in their transaction processing workflows. Additionally, systems should implement monitoring for any unusual transaction validation patterns that might indicate exploitation attempts. The fix addresses the core validation logic discrepancy by ensuring that Bitcoin script processing aligns with established SLP consensus rules, preventing the scenario where crafted inputs could cause inconsistent validation results. This vulnerability demonstrates the importance of maintaining up-to-date dependencies in blockchain applications and highlights the critical nature of consensus alignment in distributed ledger systems. The mitigation approach aligns with industry best practices for dependency management and security patching in cryptocurrency applications, emphasizing the need for continuous vigilance in protecting against protocol-level vulnerabilities that could undermine network integrity.
This vulnerability can be categorized under CWE-116 for improper encoding or escaping of output, and CWE-707 for improper neutralization of input, as it involves the processing of specially crafted inputs that cause inconsistent behavior in the validation system. From an ATT&CK perspective, this maps to T1059.001 for command and scripting interpreter and T1553.006 for sign tool substitution, as exploitation requires crafting specific script patterns that bypass normal validation mechanisms. The vulnerability represents a significant risk to SLP ecosystem participants and underscores the importance of proper input validation in blockchain libraries. The fix implemented in version 0.21.4 addresses the root cause by strengthening the validation logic to ensure consistent interpretation of Bitcoin scripts against established SLP consensus rules, thereby preventing the potential hard-fork scenario that could have resulted from the original implementation flaw.