CVE-2025-21482 in Snapdragon Auto
Summary
by MITRE • 09/24/2025
Cryptographic issue while performing RSA PKCS padding decoding.
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Analysis
by VulDB Data Team • 07/04/2026
This cryptographic vulnerability manifests during the decryption process of RSA PKCS#1 v1.5 padding schemes where improper handling of padding validation creates opportunities for attackers to exploit timing variations and error messages. The flaw typically occurs when the cryptographic library fails to perform constant-time comparison operations during padding verification, allowing adversaries to distinguish between different types of padding errors through timing analysis or exception handling differences. This vulnerability directly relates to weakness category CWE-327 which addresses the use of weak cryptographic algorithms and improper implementation of cryptographic padding schemes. The issue enables attackers to perform adaptive chosen ciphertext attacks that can ultimately lead to the complete decryption of RSA encrypted messages without possessing the private key, representing a critical security flaw in asymmetric cryptography implementations.
The operational impact of this vulnerability extends beyond simple data confidentiality breaches as it fundamentally compromises the security assurances provided by RSA encryption. Attackers can leverage this weakness to recover session keys, decrypt sensitive communications, or even impersonate systems within secure networks. The vulnerability is particularly dangerous in web applications, secure communication protocols, and cryptographic libraries where RSA is used for key exchange or digital signatures. When combined with other attack vectors such as side-channel timing attacks or fault injection techniques, the impact becomes exponentially more severe. This weakness affects implementations that follow the PKCS#1 v1.5 standard but fail to properly validate padding in a time-constant manner, making it prevalent across numerous cryptographic libraries including OpenSSL and various proprietary implementations.
Mitigation strategies for this vulnerability require immediate implementation of constant-time comparison algorithms during padding validation processes to prevent timing side-channel attacks. Organizations must ensure their cryptographic libraries are updated to versions that properly implement constant-time operations for padding verification, typically through the use of dedicated cryptographic primitives designed to resist timing analysis. The recommended approach involves replacing traditional conditional comparisons with bitwise operations that execute in constant time regardless of input values. Additionally, implementing proper error handling that does not leak information about padding validation failures through different error messages or execution paths prevents attackers from distinguishing between malformed padding and other types of errors. Security teams should also consider migrating to newer padding schemes such as OAEP (Optimal Asymmetric Encryption Padding) which provide stronger security guarantees against adaptive chosen ciphertext attacks and are less susceptible to timing-based exploitation techniques. Regular cryptographic audits and penetration testing should include validation of padding implementation consistency to ensure that all security controls remain effective against evolving attack methodologies.