CVE-2016-1000340 in JCE Provider
Summary
by MITRE
In the Bouncy Castle JCE Provider versions 1.51 to 1.55, a carry propagation bug was introduced in the implementation of squaring for several raw math classes have been fixed (org.bouncycastle.math.raw.Nat???). These classes are used by our custom elliptic curve implementations (org.bouncycastle.math.ec.custom.**), so there was the possibility of rare (in general usage) spurious calculations for elliptic curve scalar multiplications. Such errors would have been detected with high probability by the output validation for our scalar multipliers.
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Analysis
by VulDB Data Team • 09/13/2025
The vulnerability identified as CVE-2016-1000340 affects the Bouncy Castle JCE Provider library versions 1.51 through 1.55, representing a critical flaw in the mathematical computation components that underpin elliptic curve cryptographic operations. This issue stems from a carry propagation bug within the raw mathematical classes, specifically within the org.bouncycastle.math.raw.Nat??? package which serves as the foundational arithmetic layer for cryptographic implementations. The flaw manifests in the squaring operations of these raw math classes, which are subsequently leveraged by the custom elliptic curve implementations found in org.bouncycastle.math.ec.custom.** package structures.
The technical nature of this vulnerability falls under CWE-682, which represents incorrect arithmetic operations, specifically involving mathematical computation errors that can lead to incorrect results. The carry propagation bug within the raw mathematical operations creates conditions where elliptic curve scalar multiplications may produce spurious calculations that deviate from the expected mathematical outcomes. This type of error is particularly concerning in cryptographic contexts where mathematical precision is paramount for security guarantees. The vulnerability operates at a low-level mathematical implementation, making it particularly insidious as it affects the fundamental arithmetic operations that cryptographic algorithms depend upon for their correctness and security properties.
The operational impact of this vulnerability extends beyond simple computational errors, as it introduces potential security risks through the possibility of incorrect elliptic curve operations that could compromise the integrity of cryptographic implementations. While the flaw is described as rare in general usage, its potential to affect elliptic curve scalar multiplication operations means that it could theoretically be exploited in scenarios where attackers might attempt to manipulate cryptographic computations or where the mathematical errors could be amplified through specific attack vectors. The vulnerability affects the core mathematical libraries that support custom elliptic curve implementations, which are commonly used in various cryptographic applications including digital signatures, key exchange protocols, and certificate validation systems. The probability of detection for these errors is high due to output validation mechanisms built into the scalar multiplier implementations, yet this does not eliminate the risk of undetected errors that could potentially compromise cryptographic security.
Mitigation strategies for this vulnerability require immediate upgrading to Bouncy Castle JCE Provider versions 1.56 or later, where the carry propagation bug has been resolved. Organizations should conduct thorough assessments of their cryptographic implementations to identify any dependencies on the affected versions, particularly focusing on systems that utilize custom elliptic curve cryptography. The fix addresses the root cause by correcting the carry propagation logic in the raw mathematical operations, ensuring that squaring computations produce mathematically correct results. Security teams should implement monitoring for any unusual cryptographic behavior or computational errors that might indicate the presence of this vulnerability in older versions. Additionally, organizations should consider implementing automated dependency checks to prevent deployment of vulnerable library versions in production environments, as this type of mathematical error can have cascading effects throughout cryptographic systems that depend on precise arithmetic operations. The vulnerability demonstrates the critical importance of mathematical precision in cryptographic implementations and aligns with ATT&CK technique T1059.001 for operating system command and script injection, where flawed mathematical operations could potentially be exploited through indirect means in cryptographic contexts.