CVE-2015-3298 in ykneo-openpgp
Summary
by MITRE • 03/30/2022
Yubico ykneo-openpgp before 1.0.10 has a typo in which an invalid PIN can be used. When first powered up, a signature will be issued even though the PIN has not been validated.
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Analysis
by VulDB Data Team • 04/01/2022
The vulnerability identified as CVE-2015-3298 affects Yubico ykneo-openpgp library versions prior to 1.0.10, representing a critical security flaw in cryptographic hardware authentication mechanisms. This issue stems from a simple yet dangerous typo in the library's implementation that undermines the fundamental security model of the device. The flaw occurs during the device's initial power-up sequence where the system fails to properly validate the Personal Identification Number before issuing cryptographic signatures, creating a window of opportunity for unauthorized cryptographic operations.
The technical nature of this vulnerability aligns with CWE-284, which addresses improper access control in software implementations. The typo in the validation logic essentially bypasses the PIN verification process, allowing malicious actors to perform signature operations without proper authentication. This represents a fundamental breakdown in the security architecture where the device's trust model is compromised, as it operates under the assumption that valid PIN validation has occurred when in reality no such validation takes place during the initial boot sequence. The cryptographic signatures generated during this unauthenticated state can be exploited to perform unauthorized operations that should require proper authentication.
From an operational perspective, this vulnerability creates significant risks for users relying on the YubiKey for secure cryptographic operations. Attackers who gain physical access to a YubiKey during its initial power-up phase can exploit this flaw to generate valid signatures without knowing the correct PIN, effectively nullifying the device's primary security mechanism. The impact extends beyond simple unauthorized access to include potential data integrity violations and authentication bypass scenarios that could compromise entire cryptographic workflows. This vulnerability particularly affects systems where YubiKey authentication is used for secure email encryption, code signing, or digital identity verification, as the compromised device can be used to forge signatures that appear legitimate.
The mitigation strategy for CVE-2015-3298 requires immediate upgrading to ykneo-openpgp version 1.0.10 or later, which contains the corrected validation logic. Organizations should also implement comprehensive device management policies that ensure all YubiKey devices are updated to the latest secure versions. Security teams must conduct inventory audits to identify affected devices and establish procedures for regular firmware and software updates. Additionally, users should be educated about the importance of proper device initialization sequences and the risks associated with leaving devices in unauthenticated states. This vulnerability demonstrates the critical importance of thorough code review processes and automated testing for authentication mechanisms, as even seemingly minor typos can create significant security weaknesses that can be exploited in real-world scenarios.