CVE-2018-12915 in PBC
Summary
by MITRE
In libpbc.a in PBC through 2017-03-02, there is a buffer over-read in calc_hash in map.c.
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Analysis
by VulDB Data Team • 03/29/2023
The vulnerability identified as CVE-2018-12915 represents a critical buffer over-read flaw within the PBC cryptographic library version 2017-03-02 and earlier. This issue resides in the libpbc.a component specifically within the calc_hash function located in the map.c source file. The flaw manifests when the library processes cryptographic hash calculations, creating a scenario where memory access extends beyond the boundaries of allocated buffers. Such buffer over-read conditions typically occur when a program reads data beyond the intended memory limits, potentially exposing sensitive information or causing application instability.
The technical implementation of this vulnerability stems from inadequate bounds checking within the cryptographic hash calculation routine. When the calc_hash function processes input data, it fails to properly validate buffer limits, allowing subsequent memory reads to access adjacent memory locations that may contain uninitialized data, sensitive cryptographic keys, or other confidential information. This type of flaw falls under the CWE-125 weakness category, which specifically addresses out-of-bounds read vulnerabilities in software implementations. The vulnerability's impact is particularly severe in cryptographic contexts where memory corruption can lead to information disclosure or potential key compromise.
From an operational perspective, this vulnerability poses significant risks to systems utilizing the PBC library for cryptographic operations, particularly those involving pairing-based cryptography. Attackers could potentially exploit this flaw to extract sensitive data from memory, including cryptographic keys, session information, or other confidential parameters that might be stored in adjacent memory regions. The over-read condition could be leveraged in various attack scenarios including information disclosure attacks, where adversaries might gain access to cryptographic material that should remain protected. This vulnerability directly impacts the integrity and confidentiality of cryptographic operations, making it a critical concern for security-conscious implementations.
The exploitation of CVE-2018-12915 aligns with several tactics described in the MITRE ATT&CK framework, particularly those related to credential access and defense evasion techniques. The vulnerability could enable adversaries to perform information gathering activities by extracting memory contents, potentially leading to further compromise of cryptographic systems. Organizations implementing cryptographic solutions using vulnerable PBC versions face heightened risk of data breaches and cryptographic key exposure. The flaw's remediation requires updating to patched versions of the PBC library, ensuring proper bounds checking in hash calculation functions, and implementing comprehensive memory validation procedures to prevent similar buffer over-read conditions from occurring in other cryptographic implementations. Security teams should prioritize patching affected systems and conduct thorough vulnerability assessments of cryptographic dependencies to prevent exploitation of similar memory corruption issues.