CVE-2018-12433 in cryptlib
Summary
by MITRE
** DISPUTED ** cryptlib through 3.4.4 allows a memory-cache side-channel attack on DSA and ECDSA signatures, aka the Return Of the Hidden Number Problem or ROHNP. To discover a key, the attacker needs access to either the local machine or a different virtual machine on the same physical host. NOTE: the vendor does not include side-channel attacks within its threat model.
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Analysis
by VulDB Data Team • 08/05/2024
The vulnerability identified as CVE-2018-12433 represents a significant cryptographic side-channel attack affecting cryptlib versions 3.4.4 and earlier. This flaw specifically targets DSA and ECDSA signature algorithms, exposing them to memory-cache based attacks that exploit the Return Of the Hidden Number Problem or ROHNP. The vulnerability stems from the implementation's susceptibility to cache timing attacks where an attacker can infer sensitive cryptographic key information through monitoring cache behavior during signature operations.
The technical exploitation of this vulnerability requires an attacker to have access to either the local machine or a separate virtual machine operating on the same physical host. This constraint aligns with common side-channel attack methodologies where the attacker must be in close proximity to the target system or share the same hardware infrastructure. The attack leverages the inherent characteristics of memory cache behavior during cryptographic computations, allowing for the extraction of private key components through statistical analysis of cache access patterns.
This vulnerability directly relates to CWE-310, which encompasses cryptographic weaknesses and specifically addresses side-channel attacks that can compromise cryptographic implementations. The attack methodology follows established patterns described in the ATT&CK framework under the technique of "Credential Access: Steal or forge TLS certificates" and "Execution: Memory Injection" where the attacker gains access to cryptographic keys through indirect means rather than direct exploitation of software bugs.
The operational impact of this vulnerability extends beyond simple cryptographic compromise, as it fundamentally undermines the security assumptions of cryptographic implementations that rely on constant-time execution and memory isolation. Systems utilizing cryptlib for DSA or ECDSA signature operations become vulnerable to key recovery attacks that can compromise the entire cryptographic infrastructure. Organizations using affected versions of cryptlib face potential exposure of private keys, leading to unauthorized signature generation, certificate forgery, and complete breakdown of authentication mechanisms relying on these algorithms.
Mitigation strategies for this vulnerability include upgrading to cryptlib versions that address the side-channel concerns and implementing additional hardware-level protections such as cache isolation, memory encryption, and virtual machine isolation measures. Organizations should also consider deploying additional monitoring systems to detect unusual cache access patterns and implement proper security controls to prevent cross-VM attacks. The vendor's acknowledgment that side-channel attacks are outside their threat model highlights the importance of proactive security measures and comprehensive threat modeling that includes indirect attack vectors.